03118nas a2200193   4500008004100000022001400041245014800055210006900203260007100272300001600343490000800359520233400367100001402701700002302715700002702738700001702765700001902782856012302801       2009                        eng d  a1932-744700aMechanistic study of surface functionalization of enzyme lysozyme synthesized Ag and Au nanoparticles using surface enhanced raman spectroscopy0 aMechanistic study of surface functionalization of enzyme lysozym  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC  a21493-215000 v1133 a<p>The fate of bioactivity of biomolecules such as enzymes, proteins, and even drug molecules is greatly affected by the conformational changes in the proximity of the solid surfaces. This interaction is the key to the potential of their further applications as biosensors, in drug delivery, etc. With increasing interest in the biofunctionalization of noble metal nanoparticles for various applications, it is important to precisely investigate the functional groups responsible for binding with the nanoparticle surfaces and probable structural changes in the structure of the biomolecules as both are key factors affecting the bioactivity of these molecules once they are tagged onto the nanoparticle surfaces. However, it is not an easy task to probe these properties, especially for bigger Molecules such as enzymes and proteins. Surface-enhanced Raman spectroscopy (SERS) has been used extensively in the detection of biomolecules and study of their conformation on noble metal surfaces since its discovery because of its high sensitivity. This technique is capable of detecting changes in the secondary structure and the effects of surrounding environment on the biomolecule in the proximity of nanoscopic rough metal surfaces. In this study, we have used this technique to precisely determine the functional groups responsible in the Surface capping of Ag and Au nanoparticles synthesized by the hen egg derived enzyme lysozyme. The sharp and intense Stokes Raman shift peaks observed around 704, 866, 1519, and 1598 cm(-1), in the case of Ag nanoparticles, which are assigned to tryptophan, tyrosine, phenylalanine, and histidine residues, clearly indicate the involvement of these residues for surface passivation of the Ag nanoparticle surface. The Ag-N peak situated around 236 cm(-1) was also seen in the spectra, showing that probably the amine group of lysozyme is responsible in binding to the Ag nanoparticle surface. Similarly, in the case of Au nanoparticles, we observed sharp and intense peaks around 1583, 1545, and 1584 cm(-1) which were assigned to above-mentioned amino acid residues, indicating that a similar mechanism is also responsible for the binding of lysozyme molecules at the Au nanoparticle surface. In both cases peaks for the amide III band (C-N-H) around 1250 cm(-1) were also observed.</p>1 aDas, Raja1 aJagannathan, Ramya1 aSharan, Chandrashekhar1 aKumar, Umesh1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/mechanistic-study-surface-functionalization-enzyme-lysozyme-synthesized-ag-and-au-002054nas a2200205   4500008004100000022001400041245010900055210006900164260007100233300001400304490000800318520127800326100002001604700001401624700001901638700002501657700002701682700001901709856012001728       2010                        eng d  a1932-744700aEffect of reduced particle size on the magnetic properties of chemically synthesized BiFeO3 nanocrystals0 aEffect of reduced particle size on the magnetic properties of ch  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a2108-21150 v1143 a<p>Here, we report the effect of reduction in particle size on the temperature dependent magnetization of chemically synthesized BiFeO3 nanocrystals with average grain size of 55 nm. The X-ray photoelectron spectroscopy results show a significant broadening of binding energy peaks associated to Fe3+ 2p(3/2) core levels due to the reduced size. Additionally, due to the nanosize effect, the M-H loops show a significant coercivity starting from 390 K with an anomaly located in the vicinity of 150 K in our H-c vs T as well as M-r/M-s(50 kOe) vs T curves. At this temperature, both H-c and M-r/M-s(50 kOe) undergo minima. Additionally, our results for the first time show the evidence of existence of a low temperature anomaly due to spin-glass transition in the range from 40-44 K in the field cooled magnetization curves. In bulk single crystals, this transition is reported to be situated at around 50 K, however, this transition remained so far undiscovered in the recent studies on BiFeO3 nanoparticles due to the insufficient temperature resolution. The significant shift in this transition toward lower temperature can be attributed to size dependent effects. Our results clearly present new information on the size dependent properties of BiFeO3 nanoparticles.</p>1 aJaiswal, Adhish1 aDas, Raja1 aVivekanand, K.1 aAbraham, Priya, Mary1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/effect-reduced-particle-size-magnetic-properties-chemically-synthesized-bifeo3-003023nas a2200337   4500008004100000022001400041245008600055210006900141260012500210300001100335490000800346520187100354653002202225653002502247653001802272653001802290653002002308653001802328653001702346653001202363653001802375653003102393100002002424700001402444700001902458700001702477700002502494700002702519700001902546856012002565       2010                        eng d  a0021-897900aMagnetic and dielectric properties and Raman spectroscopy of GdCrO3 nanoparticles0 aMagnetic and dielectric properties and Raman spectroscopy of GdC  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJAN  a0139120 v1073 a<p>The rare earth orthochromites are extremely interesting due to the richness of their optical, dielectric, and magnetic properties as well as due to their multiferroic properties which make them suitable materials to study in the nanoregime. However, the wet-chemical synthesis of these materials in nanosize is nontrivial. Here, we report for the first time, the detailed Raman spectra as well as magnetic and dielectric properties of chemically synthesized GdCrO3 nanoparticles of size ranging from 40 to 60 nm. The magnetic properties are dictated by competing Cr3+-Cr3+, Gd3+-Cr3+, and Gd3+-Gd3+ superexchange interactions in different temperature regions, resulting into an antiferromagnetic ordering at 167 K due to the Cr3+-Cr3+ followed by weak ferromagnetic ordering due to the onset of Cr3+-Gd3+ interactions. At lower temperature, it shows weak antiferromagnetic ordering due to Gd3+-Gd3+ interaction. Below 95 K, GdCrO3 nanoparticles showed the presence of negative magnetization due to Gd3+ and Cr3+ interactions resulting into weak ferromagnetic coupling. The Raman spectroscopy shows the characteristic Raman shifts indicating that below 450 cm(-1), Gd3+ ions play a dominant role in determining the phonon frequencies of GdCrO3, and above 450 cm(-1), the Cr+3 ions dominate. We also present for the first time the low temperature dielectric constant and loss tangent data for GdCrO3 in a broad temperature and frequency range. The dielectric constant shows a decrease in comparison to the bulk values due to the size dependent effects. It also shows a peak centered at around 320 K above which it shows a sharp decrease. The dielectric loss value in GdCrO3 nanoparticles is quite small and shows an interesting frequency dependent anomaly at lower temperature which might be due to the coupling between magnetic and dielectric order parameters.</p>10adielectric losses10agadolinium compounds10aMagnetisation10aMultiferroics10ananofabrication10aNanoparticles10apermittivity10aphonons10aRaman spectra10asuperexchange interactions1 aJaiswal, Adhish1 aDas, Raja1 aVivekanand, K.1 aMaity, Tuhin1 aAbraham, Priya, Mary1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/magnetic-and-dielectric-properties-and-raman-spectroscopy-gdcro3-nanoparticles-002571nas a2200181   4500008004100000022001400041245008600055210006900141260007100210300001600281490000800297520189100305100001402196700002002210700002702230700001902257856011302276       2010                        eng d  a1932-744700aOrigin of magnetic anomalies below the neel temperature in nanocrystalline LuMnO30 aOrigin of magnetic anomalies below the neel temperature in nanoc  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL  a12104-121090 v1143 a<p>Rare earth manganites crystallize in distorted orthorhombic perovskite or hexagonal structures and exhibit quite interesting optical and magnetic properties dictated by the size of the rare earth ion. Many of these materials might exhibit both ferroelectric and magnetic ordering as well as magnetoelectric coupling. However, their physical properties at reduced particle sizes remain underexplored due to the challenges associated with their synthesis with a proper control over the crystalline phase. Here, we report the wet-chemical synthesis of the hexagonal phase of nanocrystalline LuMnO3 with an average crystallite size of similar to 32 nm. The room-temperature Raman spectroscopy data are consistent with the calculated values of isomorphous hexagonal RMnO3 (R = rare earth atom) compounds with P6(3)cm symmetry. The UV-vis-NIR spectra recorded in the diffused reflectance mode at room temperature show electronic transitions at 1.7 eV (729 nm), 2.3 eV (539 nm), and 5 eV (258 nm). The magnetization measurements show that the Neel temperature for the LuMnO3 is situated at around 89 K, which is in close proximity to the reported value of the bulk phase. We also observed two unique and field-dependent magnetic anomalies that were predicted earlier but never reported experimentally. The first anomaly is observed as a sharp bifurcation in the ZFC-FC curves below 44 K at a 100 Oe applied field, which is accompanied with a sudden rise in the coercivity and magnetization. A second transition is observed at 12 K as a sharp peak in the ZFC curves, which is accompanied with a dip in coercivity. We attribute the transition at 44 K to the reorientation of the Mn3+ ions due to the Dzyaloshinskii-Moriya interaction, and the transition at 12 K is explained by weak antiferromagnetic coupling between Mn-O-Mn in the ab plane, which becomes dominant at lower temperatures.</p>1 aDas, Raja1 aJaiswal, Adhish1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/origin-magnetic-anomalies-below-neel-temperature-nanocrystalline-lumno3-001507nas a2200181   4500008004100000022001400041245012300055210006900178260007100247300001400318490000700332520078300339100002101122700001401143700001901157700002001176856012901196       2010                        eng d  a1528-748300aStructural, magnetic, and gas adsorption study of a two-dimensional tetrazole-pyrimidine based metal-organic framework0 aStructural magnetic and gas adsorption study of a twodimensional  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN  a2475-24780 v103 a<p>A new two-dimensional (2D) metal-organic framework, Cu-TP-1, has been synthesized under solvothermal conditions (DMF) from the transition metal cation Cu(II) and 2-tetrazole pyrimidine (C5H5N6, H-TP). The structure has been determined by single crystal X-ray crystallography which shows a (6,3) honeycomb 2D net with perpendicular one-dimensional channels. Permanent porosity of Cu-TP-1 has been determined by the nitrogen adsorption isotherm. Cu-TP-1 show interesting H-2 and CO2 uptake. CO2 uptake of Cu-TP-1 (at 298 K, 1 atm pressure) is seen to be comparable to the recently reported ZIF-95 which outperforms ZIF-100 and BPL carbon. The magnetic properties show an antiferromagnetically coupled Cu ... Cu interaction down to 8 K with a Weiss temperature around 108 K.</p>1 aPachfule, Pradip1 aDas, Raja1 aPoddar, Pankaj1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/structural-magnetic-and-gas-adsorption-study-two-dimensional-tetrazole-pyrimidine-based-002541nas a2200205   4500008004100000022001400041245014000055210006900195260007100264300001600335490000800351520173100359100002002090700001402110700001702124700001902141700002702160700001902187856012902206       2010                        eng d  a1932-744700aTemperature-dependent raman and dielectric spectroscopy of BiFeO3 nanoparticles: signatures of spin-phonon and magnetoelectric coupling0 aTemperaturedependent raman and dielectric spectroscopy of BiFeO3  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL  a12432-124390 v1143 a<p>We report the temperature-dependent Raman and dielectric spectroscopy of chemically synthesized BiFeO3 nanoparticles (average size similar to 50-60 nm). The Raman spectra (90-700 K) show two sets of transitions in the lowest Raman E mode, associated with Bi-O bond motion situated in close proximity to the spin reorientation transitions reported for BiFeO3, thereby indicating the existence of possible coupling between magnons and phonons for particle size below the helical order parameter (62 nm). These transitions are slightly shifted in temperature in comparison to the bulk single crystals. We also observe a step-like behavior in Raman peak position around the Neel temperature, suggesting that the phonons are influenced by the magnetic ordering in nanosized BiFeO3. The heat-flow measurements show two sharp endothermic peaks at 1094 and 1223 K representing rhombohedral to orthorhombic or monoclinic transition followed by transition into the cubic phase above 1200K. The low temperature (20-325 K), frequency-dependent (1-10(6) Hz) dielectric constant and loss tangent measurements show that the loss tangent (similar to 10(-3)) and ac conductivity values (similar to 10(-8) Ohm(-1)-cm(-1)) are orders of magnitude lower than the reported values for BiFeO3 ceramics, indicating high levels of ionic purity of our samples. The real part of the permittivity shows a slight reduction in its value (similar to 30) in comparison to the bulk single crystals. Similar to the Stokes Raman shift, its temperature-dependent dielectric constant also shows four weak anomalies at similar to 85, 168, 205, and 230 K situated in close proximity to the spin reorientation transitions, indicating magnetoelectric coupling.</p>1 aJaiswal, Adhish1 aDas, Raja1 aMaity, Tuhin1 aVivekanand, K.1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/temperature-dependent-raman-and-dielectric-spectroscopy-bifeo3-nanoparticles-signatures-001213nas a2200193   4500008004100000022001400041245011500055210006900170260011000239300001600349490000700365520042700372100001700799700001400816700002500830700001900855700002000874856012500894       2011                        eng d  a1359-734500aDesign and in situ synthesis of a Cu-based porous framework featuring isolated double chain magnetic character0 aDesign and in situ synthesis of a Cubased porous framework featu  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a11008-110100 v473 a<p>A Cu-based double chain MOF was synthesized in hydrothermal conditions using an in situ ligand formation method. This double chain MOF shows temperature dependent ferromagnetic (long range ordering) and antiferromagnetic (intra double chain) coupling. The magnetic behaviour originating from the individual double chain remains almost same even after structural collapse due to the removal of guest water molecules.</p>1 aDey, Chandan1 aDas, Raja1 aSaha, Binoy, Krishna1 aPoddar, Pankaj1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/design-and-situ-synthesis-cu-based-porous-framework-featuring-isolated-double-chain-001989nas a2200181   4500008004100000022001400041245006800055210006800123260012500191300001100316490000800327520130000335100002001635700001401655700001701669700001901686856010201705       2011                        eng d  a0021-897900aDielectric and spin relaxation behaviour in DyFeO3 nanocrystals0 aDielectric and spin relaxation behaviour in DyFeO3 nanocrystals  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScDEC  a1243010 v1103 a<p>We report the temperature and frequency dependent dielectric measurements and ac magnetic susceptibility of chemically synthesized DyFeO3 nanoparticles (size similar to 50-60 nm). The measurement of the dielectric properties was carried out in a broad temperature (20-325 K) and frequency (1-10(6) Hz) range. The non-Debye type dipolar relaxation phenomenon was observed in the DyFeO3 nanoparticles, as confirmed by the Cole-Cole plots. The higher values of epsilon' at the lower frequencies are explained on the basis of the Maxwell-Wagner model. The Cole-Cole analysis enabled us to separate the contribution of relaxation times, resistance and capacitance in grain and grain boundaries in DyFeO3 nanocrystals. We found that with increasing temperature, the contribution of grain boundary resistance increases in comparison to the grain resistance. We also performed spin relaxation studies in a broad temperature and frequency range. Both the in-phase (chi') and out-of-phase (chi `') components of the ac magnetic susceptibilities of the DyFeO3 nanoparticles show a clear evidence at spin reorientation transition around 70K and T-N (Dy) around 4K as reported by us in our earlier study using the dc magnetic behaviour. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3669154]</p>1 aJaiswal, Adhish1 aDas, Raja1 aMaity, Tuhin1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/dielectric-and-spin-relaxation-behaviour-dyfeo3-nanocrystals-001846nas a2200181   4500008004100000022001400041245008000055210006900135260012500204300001100329490000800340520112800348100001401476700002001490700002701510700001901537856010801556       2011                        eng d  a0021-897900aEffect of particle size and annealing on spin and phonon behavior in TbMnO30 aEffect of particle size and annealing on spin and phonon behavio  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScMAR  a0643090 v1093 a<p>Interest has grown to study TbMnO3 as it was recently reported to show a gigantic magnetoelectric effect. Here, we report the synthesis and detailed magnetic and Raman spectroscopy study on TbMnO3 particles of size similar to 25 nm and 2-3 mu m, respectively. The incommensurate-commensurate (lock-in) transition, usually observed at 27 K for bulk phase of TbMnO3 was not observed in susceptibility versus T curve but was seen at 30 K in the coercivity versus T curve in similar to 25 nm particles. This transition, which is due to the spin modulation length scale, gets weakened in nanosize due to the increased intrinsic lattice strain observed in 2-3 mu m particles, due to the effect of increased particle size. The increased value of magnetization in the 2-3 mu m sample was attributed to double exchange interactions between Mn+3 and Mn+4 spins. The role of annealing related effects on the fate of the Neel temperature for TbMnO3 was investigated. Raman spectroscopy indicated a decrease in the lattice distortion for similar to 25 nm particles. (c) 2011 American Institute of Physics. [doi:10.1063/1.3563571]</p>1 aDas, Raja1 aJaiswal, Adhish1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/effect-particle-size-and-annealing-spin-and-phonon-behavior-tbmno3-001635nas a2200253   4500008004100000022001400041245008700055210006900142260010600211300001000317490000800327520071300335653002201048653001501070653002901085653001801114100003401132700002601166700001401192700001701206700001901223700002101242856011801263       2011                        eng d  a0038-109800aInvestigations of magnetic and dielectric properties of cupric oxide nanoparticles0 aInvestigations of magnetic and dielectric properties of cupric o  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJAN  a55-600 v1513 a<p>Cupric oxide nanoparticles of similar to 8-10 nm width and 40-45 nm length self assembled as large particles similar to 1-1 5 mu m have been investigated in the 10-325 K temperature range using magnetic and dielectric measurements In magnetic measurements a single broad peak at similar to 230 K in a zero field cooled sample has been observed Coercivity in magnetization measurements at 10 K suggests that the nanoparticles are core-shell type particles with an antiferromagnetic core and a ferromagnetic shell Dielectric measurements at various frequencies from 3 7 Hz to 949 kHz exhibit a sharp peak at 284 K followed by weak anomalies around 213 and 230 K (C) 2010 Elsevier Ltd All rights reserved</p>10aCuO nanoparticles10aDielectric10aFerroelectric transition10aFerromagnetic1 aBhalerao-Panajkar, Rohini, S.1 aShirolkar, Mandar, M.1 aDas, Raja1 aMaity, Tuhin1 aPoddar, Pankaj1 aKulkarni, S., K.  uhttps://library.ncl.res.in/content/investigations-magnetic-and-dielectric-properties-cupric-oxide-nanoparticles-001760nas a2200229   4500008004100000022001400041245010300055210006900158260009500227300001200322490000800334520089600342653003601238653001901274653000801293100002201301700002201323700001401345700001901359700002601378856012601404       2011                        eng d  a0022-459600aRoom temperature ferromagnetism in undoped and Fe doped ZnO nanorods: microwave-assisted synthesis0 aRoom temperature ferromagnetism in undoped and Fe doped ZnO nano  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcFEB  a391-4000 v1843 a<p>One-dimensional (1D) undoped and Fe doped ZnO nanorods of average length similar to 1 mu m and diameter similar to 50 nm have been obtained using a microwave-assisted synthesis. The magnetization (M) and coercivity (H-c) value obtained for undoped ZnO nanorods at room temperature is similar to 5 X 10(-3) emu/g and similar to 150 Oe, respectively. The Fe doped ZnO samples show significant changes in M -H loop with increasing doping concentration. Both undoped and Fe doped ZnO nanorods exhibit a Curie transition temperature (T-c) above 390 K. Electron spin resonance and Mossbauer spectra indicate the presence of ferric ions. The origin of ferromagnetism in undoped ZnO nanorods is attributed to localized electron spin moments resulting from surface defects/vacancies, where as in Fe doped samples is explained by F center exchange mechanism. (C) 2010 Published by Elsevier Inc.</p>10aDiluted magnetic semiconductors10aNanostructures10aZnO1 aLimaye, Mukta, V.1 aSingh, Shashi, B.1 aDas, Raja1 aPoddar, Pankaj1 aKulkarni, Sulabha, K.  uhttps://library.ncl.res.in/content/room-temperature-ferromagnetism-undoped-and-fe-doped-zno-nanorods-microwave-assisted-002511nas a2200181   4500008004100000022001400041245013100055210006900186260007100255300001400326490000700340520177900347100002102126700001402147700001902161700002002180856012902200       2011                        eng d  a1528-748300aSolvothermal synthesis, structure, and properties of metal organic framework isomers derived from a partially fluorinated link0 aSolvothermal synthesis structure and properties of metal organic  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR  a1215-12220 v113 a<p>Solvothermal reactions of Cu(NO3)(2) center dot 3H(2)O with 4,4'-(hexafluoroisopropylidene) bis(benzoic acid) (C17H10F6O4, H(2)hfbba) and terminal monodentate ligand 3-methyl pyridine (3-picoline/3-mepy) in the presence of N, N-dimethyl formamide (DMF) and N,N-diethyl formamide (DEF) solvents gave rise to two structurally different two-dimensional (2D) fluorinated metal organic frameworks (F-MOFs). The effect of the choice of solvent has been clearly reflected in the structures obtained. The F-MOFs reported in this paper are formulated as [Cu-2(hfbba)(2)(3-mepy)(2)] center dot (DMF)(2)(3-mepy) (F-MOF-4), [Cu-2(hfbba)(2)(3-mepy)(2)] (Cu-F-MOF-4B), and [Zn-2(hfbba)(2)(3-mepy)(2)] center dot (3-mepy) (Zn-F-MOF-4B) which displays interesting 2D structures with and without interdigitation depending on the solvent used. The structures of these F-MOFs have been determined by X-ray crystallography and further identified by IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). The effect of interdigitation has been reflected in the gas adsorption and magnetic properties of these F-MOFs. These F-MOFs also show comparable H-2 and CO2 uptake depending on their structural variation. Temperature-dependent magnetic susceptibility measurements over a wide range of temperatures exhibit dominantly short-range antiferromagnetic behavior, with weak ferromagnetic behavior showing up at very low temperatures, which is evident from opening of the hysteresis loop with a finite value of coercivity in both F-MOF-4 and Cu-F-MOF-4B. We observed a smaller value of mu(eff) per Cu atom and coercivity in Cu-F-MOF-4B than the F-MOF-4 due to relatively larger distances between the neighboring dicopper paddlewheel secondary building unit.</p>1 aPachfule, Pradip1 aDas, Raja1 aPoddar, Pankaj1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/solvothermal-synthesis-structure-and-properties-metal-organic-framework-isomers-derived-002006nas a2200193   4500008004100000022001400041245013000055210006900185260007100254300001200325490000700337520124800344100001701592700001401609700002101623700001901644700002001663856012901683       2011                        eng d  a1528-748300aStructural and selective gas adsorption studies of polyoxometalate and tris(ethylenediamine) cobalt(III) based ionic crystals0 aStructural and selective gas adsorption studies of polyoxometala  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN  a139-1460 v113 a<p>Seven new ionic solids built on polyoxometalate anions and [Co(en)(3)](3+) cations, namely, [Co(en)(3)Mo(8)O(26)(H(3)O)-(Cl)](DMF)(4)(H(2)O) (Co-Mo(8)-DMF), [alpha-PW(12)O(40)][Co(en)(3)]center dot 6DMF (Co-W(12)P-DMF), [alpha-PW(12)O(40)][Co(en)(3)]center dot 6DEF (Co-W(12)P-DEF), [alpha-PMo(12)O(40)][Co(en)(3)]center dot 5.5DMF (Co-Mo(12)P-DMF), [alpha-PMo(12)O(40)][Co(en)(3)]center dot 6DEF (Co-Mo(12)P-DEF), [alpha-SiW(12)O(40)]-[Co(en)(3)](3/2)[Cl](1/2)center dot 6DMF center dot 3H(2)O (Co-W(12)Si-DMF), and [alpha-SiW(12)O(40)][Co(en)(3)]center dot 6DEF (Co-W(12)Si-DEF), have been synthesized from nonaqueous (DMF/DEF) media and characterized by single-crystal X-ray diffraction. We attempt to understand if [Co(en)(3)](3+) cations used in these reaction systems play a crucial role in controlling the assembly of these crystals. These ionic solids, after removal of the DMF or DEF molecules, are found to exhibit size selective H(2) adsorption properties over N(2). The amount of hydrogen adsorption was influenced by POM anion types and their orientations. CoMo(12)P-DEF has the highest (0.9 wt %) H(2) uptake, and CoW(12)P-DEF has the lowest (0.4 wt %) uptake among the series when the adsorbate pressure approached 1 atm.</p>1 aDey, Chandan1 aDas, Raja1 aPachfule, Pradip1 aPoddar, Pankaj1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/structural-and-selective-gas-adsorption-studies-polyoxometalate-and-trisethylenediamine-002015nas a2200181   4500008004100000022001400041245012300055210006900178260007100247300001400318490000700332520129100339100002101630700001401651700001901665700002001684856012901704       2011                        eng d  a0020-166900aStructural, magnetic, and gas adsorption study of a series of partially fluorinated metal-organic frameworks (HF-MOFs)0 aStructural magnetic and gas adsorption study of a series of part  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a3855-38650 v503 a<p>Four new partially fluorinated metal organic frameworks (HF-MOFs) have been synthesized under different solvothermal conditions (H2O or dimethylformamide (DMF)) from transition metal cations [Co2+ and Mn2+], 3-methyl pyridine (3-mepy) and 4,4'-(hexafluoroisopropylidene) bis(benzoic acid) (C17H10F6O4, H(2)hfbba), to determine the influence of reaction conditions on the formation of MOFs. This family of materials displays a striking degree of structural similarity depending on the solvent of synthesis. HF-MOFs synthesized from H2O [Co-HFMOF-W, Co(liffiba)(3-mepy)(H2O) and Mn-HFMOF-W, Mn(hfbba)(3-mepy)(H2O)] contain three-dimensional connectivity whereas HF-MOFs synthesized from DmF Co-HFMOF-D, [Co-2(hfbba)(2)(3-mepy)(2)]center dot(DMF)(3) and Mn-HFMOE-D, [Mn-2(hfbba)(2)(3-mepy)]center dot(H2O) are two-dimensional in nature. Co-HFMOF-W and Mn-HFMOF-W are iso-structural polymeric materials. Thermal gravimetric analysis performed on as-synthesized HP-MOFs revealed that these compounds have high thermal stability (similar to 350 degrees C). The continuous decrease of the chi T product with decreasing T for Co-HFMOF-D and Co-HFMOF-W respectively indicates the presence of antiferromagnetic exchange interaction between two Co2+ (S = 3/2) metal centers within a duster.</p>1 aPachfule, Pradip1 aDas, Raja1 aPoddar, Pankaj1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/structural-magnetic-and-gas-adsorption-study-series-partially-fluorinated-metal-organic-002882nas a2200181   4500008004100000022001400041245013600055210006900191260007100260300001400331490000800345520213500353100002002488700001402508700002702522700001902549856013202568       2011                        eng d  a1932-744700aSurface effects on morin transition, exchange bias, and enchanced spin reorientation in chemically synthesized DyFeO3 nanoparticles0 aSurface effects on morin transition exchange bias and enchanced   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a2954-29600 v1153 a<p>A giant linear magnetoelectric effect was observed by Y. Tokura's group recently in multiferroic DyFeO3, which demands a detailed investigation of its magnetic properties. Additionally, there is little information on the changes of chemical and physical properties of these materials with the reduction in particle size in spite of the potential applications of these materials nanoscale devices. As the wet-chemical synthesis of these materials in nanosize and getting a control over crystallinity and stoichiometry is nontrivial and poses a serious challenge prohibiting the study of their size-dependent properties. Here, we report the synthesis of DyFeO3 nanoparticles using a surfactantless hydrothermal method with a detailed magnetic property measurement. The as-synthesized DyFeO3 nanoparticles showed excellent crystallinitywith average particle size in the range 50-60 nm. The structural analysis indicated that they are of a distorted orthorhombic pervoslcite crystal structure. Detailed dc magnetization measurements in the temperature range of 3-350 K could isolate the presence of Dy3+-Fe3+ and Dy3+-Dy3+ superexchange interactions, which showed up as spin reorientation transitions in various temperature regions due to the differing magnitude of their interactions resulting in continuous rotation of antiferromagnetic component of Fe3+ spins with cooling of the sample. Nanosized DyFeO3 showed spin-reorientation transitions near 315 and 70K due to the Dy3+-Fe3+ interaction accompanied with an opening up of the hysteresis loop followed by antiferromagnetic ordering around 4 K due to a possible Dy3+-Dy3+ interaction. We also observed significant effect of the particle size reduction on the magnetic properties. The main effects seen. by us were in terms of (1) pronounced spontaneous spin reorientation transitions, (2) the absence of Morin transition, and (3) presence of temperature-dependent exchange bias in the DyFeO3 nanoparticles. We present a detailed mechanism to explain these features based on the interplay of Dy3+ and Fe3+ spins as well surface disorder, anisotropy, canting, and so forth.</p>1 aJaiswal, Adhish1 aDas, Raja1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/surface-effects-morin-transition-exchange-bias-and-enchanced-spin-reorientation-chemically-001264nas a2200217   4500008004100000022001400041245005800055210005800113260007400171300001400245490000700259520054300266653001700809653001800826653003000844100002000874700001400894700002700908700001900935856009200954       2011                        eng d  a1388-076400aSynthesis and optical studies of GdCrO3 nanoparticles0 aSynthesis and optical studies of GdCrO3 nanoparticles  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcMAR  a1019-10270 v133 a<p>{Here we report for the first time, a detailed synthesis mechanism of GdCrO3 nanoparticles using a surfactant-less hydrothermal method. We also report a detailed study of their structural and optical properties. The selected area electron diffraction and powder X-ray diffraction studies of GdCrO3 nanoparticles show pure phase and excellent crystallinity with average particle size around 50-60 nm. The structural analysis indicates a distorted perovskite crystal structure with lattice parameter values of a = 5.3099 +/- A 0.0022</p>10ahydrothermal10aNanoparticles10aRare earth orthochromites1 aJaiswal, Adhish1 aDas, Raja1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/synthesis-and-optical-studies-gdcro3-nanoparticles-001134nas a2200181   4500008004100000022001400041245010300055210006900158260007100227300001400298490000700312520043000319100002500749700001400774700001900788700002100807856012400828       2012                        eng d  a0020-166900aBistable dynamic coordination polymer showing reversible structural and functional transformations0 aBistable dynamic coordination polymer showing reversible structu  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG  a8317-83210 v513 a<p>A bistable dynamic coordination polymer [Ni(pca)(bdc)(0.5)(H2O)(2)] having a two-dimensional (2D) zigzag sheet structure is synthesized solvothermally. Topological analysis revealed that the frameworks have an hcb type of uninodal net. The compound exhibits guest specific reversible structural transformations accompanying reversible changes in physical properties driven by inherent flexibility and transformability.</p>1 aNagarkar, Sanjog, S.1 aDas, Raja1 aPoddar, Pankaj1 aGhosh, Sujit, K.  uhttps://library.ncl.res.in/content/bistable-dynamic-coordination-polymer-showing-reversible-structural-and-functional-002013nas a2200181   4500008004100000022001400041245013200055210006900187260011000256300001200366490000600378520124200384100001401626700002101640700002001661700001901681856013101700       2012                        eng d  a2040-336400aMetal and metal oxide nanoparticle synthesis from metal organic frameworks (MOFs): finding the border of metal and metal oxides0 aMetal and metal oxide nanoparticle synthesis from metal organic   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a591-5990 v43 a<p>Herein, for the first time, we report a generalized strategy for the successful synthesis of highly crystalline metal and metal oxide nanoparticles embedded in a carbon matrix by the controlled thermolysis of metal organic frameworks (MOFs). The rationalized synthesis strategy of a broad range of metal and metal oxides nanoparticles, such as Cu/CuO, Co/Co3O4, ZnO, Mn2O3, MgO and CdS/CdO, by thermolysis of MOFs demonstrates for the first time that metal ions with a reduction potential of -0.27 volts or higher present in MOFs always form pure metal nanoparticles during thermolysis in N-2, whereas metal ions with a reduction potential lower than -0.27 volts form metal oxide nanoparticles during thermolysis in N-2. Another point of interest is the fact that we have found a unique relationship between the nanoparticle size and the distance between the secondary building units inside the MOF precursors. Interestingly, the crystallinity of the carbon matrix was also found to be greatly influenced by the environment (N-2 and air) during thermolysis. Moreover, these nanoparticles dispersed in a carbon matrix showed promising H-2 and CO2 adsorption properties depending on the environment used for the thermolysis of MOFs.</p>1 aDas, Raja1 aPachfule, Pradip1 aBanerjee, Rahul1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/metal-and-metal-oxide-nanoparticle-synthesis-metal-organic-frameworks-mofs-finding-border-002832nas a2200193   4500008004100000022001400041245014300055210006900198260007100267300001600338490000800354520204500362100002602407700001402433700001702447700001902464700002602483856012902509       2012                        eng d  a1932-744700aObservation of enhanced dielectric coupling and room-temperature ferromagnetism in chemically synthesized BiFeO3@SiO2 core-shell particles0 aObservation of enhanced dielectric coupling and roomtemperature   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a19503-195110 v1163 a<p>We report the effect of SiO2 coating on the structural, magnetic, and dielectric properties of chemically synthesized high-purity BiFeO3 particles. The assynthesized BiFeO3 particles demonstrate properties comparable with those reported for bulk BiFeO3. On the other hand, the structural measurement on BiFeO3@SiO2 shows that the SiO2 coating has anisotropically compressed the lattice of BiFeO3 particles and stimulates the variation in the electron density. This affects magnetic and dielectric behavior of material. Frequency-dependent dielectric constant study at low temperature (20-325 K) revealed slight reduction (8-10%) in the dielectric constant of BiFeO3@SiO2 particles compared to uncoated BiFeO3 particles. The study reveals five anomalies at 234, 206, 146, 84, and 25 K located in close proximity to the linear magnetodielectric coupling and spin reorientation transitions. The loss tangent (approximate to 10(-3)) and alternating current (ac) conductivity (approximate to 10(-8) Omega(-1)cm(-1)) of BiFeO3@SiO2 particles are orders of magnitude lower than those observed for the BiFeO3 particles. The magnetic measurement shows the existence of room-temperature ferromagnetism in BiFeO3@SiO2 particles with average value of magnetic moment per Fe atom approximate to 0.030 mu(B) and appreciable coercivity as high as 120 Oe. The canted spin structure in the surface shell of BiFeO3@SiO2 particles show an enhanced magnetic property and shifted hysteresis loop. The magnetic measurement in close proximity to dielectric transitions revealed enhanced magnetization, suggesting the presence of anisotropies. It has been observed that SiO2 coating alters the properties of BiFeO3 particles. Our dielectric and magnetic measurements show enhanced coupling among the electric and magnetic ordered parameters in BiFeO3@SiO2 core-shell particles compared to uncoated BiFeO3 particles. The magnetic and dielectric properties of SiO2-coated BiFeO3 are similar to nanoparticles of BiFeO3 where interface plays a significant role.</p>1 aShirolkar, Mandar, M.1 aDas, Raja1 aMaity, Tuhin1 aPoddar, Pankaj1 aKulkarni, Sulabha, K.  uhttps://library.ncl.res.in/content/observation-enhanced-dielectric-coupling-and-room-temperature-ferromagnetism-chemically-001774nas a2200181   4500008004100000022001400041245010400055210006900159260007100228300001000299490000700309520108200316100001701398700001401415700001901429700002001448856012401468       2012                        eng d  a1528-748300aSolid phase morphological diversity of a rare vanadium cubane (V4O16) based metal organic framework0 aSolid phase morphological diversity of a rare vanadium cubane V4  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN  a12-170 v123 a<p>A Cu(II) connected V4O16-cubane based metal organic framework, Cu-2(phen)(2)(V4O8) (PO4)(4) [Cu2V4O16-2D] was synthesized under hydrothermal conditions. This is the first example of transition metal connected V4O16-cubane based MOF. X-ray single crystal data shows the alternate arrangement V4O16-cubane and Cu(phen)(O)(3) square pyramidal unit in two dimensions. These two-dimensional sheets are stacked on top of each other to form a three-dimensional architecture. Cu2V4O16-2D shows two types of solid state morphologies of the same phase, which was confirmed by scanning electron microscopy. It is noteworthy that this type of morphological difference of the solid phase in an extended metal organic hybrid material is rare and has not been perceived in the polyoxovanadate based MOFs literature. Cu2V4O16-2D was further characterized by powder X-ray diffraction (PXRD), thermal gravimetric analysis (TGA), IR-spectroscopy, scanning electron microscopy (SEM), and elemental analysis. We also studied the static magnetic and gas adsorption properties for Cu2V4O16-2D.</p>1 aDey, Chandan1 aDas, Raja1 aPoddar, Pankaj1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/solid-phase-morphological-diversity-rare-vanadium-cubane-v4o16-based-metal-organic-001223nas a2200181   4500008004100000245017000041210006900211260000800280300001400288490000700302520050100309100001900810700002200829700001400851700001900865700002700884856013000911       2012                        eng d00aSyntheses, crystal structures, and magnetic properties of metal-organic hybrid materials of Co(II) using flexible and rigid nitrogen-based ditopic ligands as spacers0 aSyntheses crystal structures and magnetic properties of metalorg  cMAR  a1571-15780 v123 a<p>{A carboxylate-based flexible ligand, 5-(4-carboxybenzyloxy)isophthalic acid (p-cbiaH(3)), readily reacts with Co(II) salts in the presence of different pyridine-based coligands such as 4-bis(4-pyridinylmethyl)piperazine (bpmp) or 1,2-di(4-pyridyl)ethylene (dpe) under hydrothermal conditions to afford two different three-dimensional (3D) coordination polymers, {[Co-4(OH)(2)(p-cbia)(2)(bpmp)-(H2O)(3)]center dot 2H(2)O}(n) (1) and {[Co-4(OH)(2)(p-cbia)(2)(dpe)(H2O)(4)]center dot 2H(2)O\</p>1 aAhmad, Musheer1 aSharma, Mamsh, K.1 aDas, Raja1 aPoddar, Pankai1 aBharadwaj, Parimal, K.  uhttps://library.ncl.res.in/content/syntheses-crystal-structures-and-magnetic-properties-metal-organic-hybrid-materials-coii-001157nas a2200181   4500008004100000245010700041210006900148260000800217300001400225490000700239520050500246100001900751700001400770700001500784700001900799700002700818856013000845       2012                        eng d00aSynthesis, characterization, and magnetic studies of coordination polymers with Co(II) and Mn(II) ions0 aSynthesis characterization and magnetic studies of coordination   cSEP  a4624-46320 v123 a<p>{An ether bridged tricarboxylic acid ligand, 5-(4-carboxybenzyloxy)isophthalic acid (p-cbiaH(3)) has been used to construct three coordination polymers with Co(II) salts in presence of different nitrogen donor ligands such as 1,4-bis(4-pyridinylmethyl)piperazine (bpmp), dipyridine-4-yl-diazene (dpd), and 4,4'-bipyridine (bpy). The products formed under hydrothermal conditions are formulated as {[Co-3(p-cbia)(2)(bpmp)(2)(H2O)(6)]center dot 10H(2)O}(n) (1), {[Co-2(p-cbiaH)(2)(dpd)(H2O)(2)]\</p>1 aAhmad, Musheer1 aDas, Raja1 aLama, Prem1 aPoddar, Pankaj1 aBharadwaj, Parimal, K.  uhttps://library.ncl.res.in/content/synthesis-characterization-and-magnetic-studies-coordination-polymers-coii-and-mnii-ions-001963nas a2200181   4500008004100000022001400041245013500055210006900190260011000259300001600369490000600385520119500391100001801586700002001604700001401624700001901638856012401657       2013                        eng d  a2046-206900aStatic and dynamic magnetic properties and effect of surface chemistry on the morphology and crystallinity of DyCrO3 nanoplatelets0 aStatic and dynamic magnetic properties and effect of surface che  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT  a26427-264320 v33 a<p>In this contribution, the structural and magnetic properties of DyCrO3 nanoplatelets, synthesized by a hydrolytic sol-gel method, have been investigated. The crystalline phase of DyCrO3 was attained at the decomposition temperature of 800 degrees C for citric acid and oxalic acid, respectively and their structural analysis indicates a distorted orthorhombic perovskite structure of the DyCrO3 nanoplatelets. The dc-magnetization curve shows the Neel temperature of similar to 144 and similar to 146 K for DyCrO3 nanoplatelets synthesized using citric acid (DCO (C)) and oxalic acid (DCO (O)), respectively. In addition, DCO (O) shows weak anomalies at similar to 22 and similar to 6 K in the zero-field-cooled and field-cooled magnetization curves. Below the Neel temperature, DCO (C) and DCO (O) exhibit cross-over from positive to negative magnetization at similar to 143 and similar to 145 K, respectively. This was attributed to a Dy3+-Cr3+ interaction, which resulted in a weak ferromagnetic coupling (seen as a small opening in the M-H curves). The low temperature transition observed at similar to 6 K can be assigned to the onset of Dy3+-Dy3+ antiferromagnetic interaction.</p>1 aGupta, Preeti1 aBhargava, Richa1 aDas, Raja1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/static-and-dynamic-magnetic-properties-and-effect-surface-chemistry-morphology-and-002069nas a2200169   4500008004100000022001400041245013400055210006900189260008100258300001100339490000700350520136000357100001401717700002001731700001901751856012901770       2013                        eng d  a0022-372700aStatic and dynamic magnetic properties and interplay of Dy3+, Gd3+ and Mn3+ spins in orthorhombic DyMnO3 and GdMnO3 nanoparticles0 aStatic and dynamic magnetic properties and interplay of Dy3 Gd3   aTEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLANDbIOP PUBLISHING LTDcJAN  a0453010 v463 a<p>Single-phase orthorhombic DyMnO3 and GdMnO3 nanoparticles in the size range 60-70 and 35-45 nm, respectively, were synthesized using a modified hydrothermal method. The magnetic property measurements of DyMnO3 nanocrystals show anomalies around similar to 43K (antiferromagnetic (AFM) coupling between Mn3+ spins) and at 7K in the form of a peak in the zero-field-cooled curve (AFM coupling between Dy3+ spins). Whereas, GdMnO3 undergoes a phase transition at similar to 42K from paramagnetic to an incommensurate-antiferromagnetic phase (ICAFM) followed by a second anomaly at similar to 22 K, which could be associated with the transition from ICAFM into a canted A-type AFM ordering of the Mn3+ spins. This transition is followed by a long-range ordering of the Gd3+ moments at 6K yielding the canting of the Gd3+ spins with a ferromagnetic (FM) component antiparallel to the FM moment of the canted Mn3+ spins. No anomaly near the Neel temperature of the Mn moments for both DyMnO3 and GdMnO3 nanoparticles was observed in ac magnetization which were observed in dc magnetization. The room temperature Raman spectra of DyMnO3 shows two most intense Raman modes at 480 and 609 cm(-1) which can be assigned to an antisymmetric Jahn-Teller stretching mode and a symmetric or breathing stretching mode, respectively, involving Mn-O bond stretching.</p>1 aDas, Raja1 aJaiswal, Adhish1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/static-and-dynamic-magnetic-properties-and-interplay-dy3-gd3-and-mn3-spins-orthorhombic-000669nas a2200181   4500008004100000245010900041210006900150260000800219300001400227490000700241100001900248700001400267700002100281700001800302700001900320700002700339856012100366       2014                        eng d00aInterchain relay of antiferromagnetic ordering in 1D Co(II) coordination polymers via pi-pi interactions0 aInterchain relay of antiferromagnetic ordering in 1D CoII coordi  cSEP  a8523-85300 v161 aAhmad, Musheer1 aDas, Raja1 aMrozinski, Jerzy1 aBienko, Alina1 aPoddar, Pankaj1 aBharadwaj, Parimal, K.  uhttps://library.ncl.res.in/content/interchain-relay-antiferromagnetic-ordering-1d-coii-coordination-polymers-pi-pi-001183nas a2200157   4500008004100000022001400041245015000055210006900205260007100274300001600345490000800361520049100369100001400860700001900874856013200893       2014                        eng d  a1932-744700aIonic control on the morphology of ytterbium manganese oxide nanorods and nanoplates in a surfactant-free synthesis and their magnetic properties0 aIonic control on the morphology of ytterbium manganese oxide nan  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN  a13268-132750 v1183 a<p>Here, we report the synthesis of multiferroic, single-crystalline ID YbMnO3 in nanoregime. By using ionic chemistry without the use of surfactant or template, we demonstrate control synthesis of one- and two-dimensional nanoparticles of YbMnO3. Magnetic properties of YbMnO3 show influence of morphology. Detailed alternating current (ac) and direct current (dc) magnetic study shows ferromagnetic interaction of Mn3+ and Yb3+ moments in nanorods of YbMnO3 below similar to 35 K.</p>1 aDas, Raja1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/ionic-control-morphology-ytterbium-manganese-oxide-nanorods-and-nanoplates-surfactant-free-001783nas a2200169   4500008004100000022001400041245006900055210006800124260007100192300001400263490000800277520117600285100002601461700001401487700001901501856009301520       2014                        eng d  a1932-744700aLarge increase in the energy product of Fe3Se4 by Fe-site doping0 aLarge increase in the energy product of Fe3Se4 by Fesite doping  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a4016-40220 v1183 a<p>Fe3Se4 possesses a large coercivity at room temperature. At lower temperature, a coercivity value up to 40 kOe has been achieved. However, due to a relatively lower saturation magnetization value, the energy product of this material is not suitable for its use as rare-earth-free hard magnetic material. Although the anisotropy and magnetic structure of Fe3Se4 have been topics of research, there is no attempt to increase the energy product. Here, we report the synthesis of Fe3-xMnxSe4 (x = 0.01-0.2) nanorods. As required for practical applications, after doping, the Curie temperature remains unchanged; however, at optimum (x = 0.03) doping of manganese ions, the magnetization of the host matrix increases significantly from 4.84 to 7.54 emu/g. The corresponding energy product value was found to be increased by more than 130%. At low temperature (10 K) the energy product shows almost a 2 order of magnitude increase (similar to 0.12 MG Oe), which makes it valuable for many low temperature applications. This improvement is a vital step for its use in some of the household applications where a large volume and relatively lower energy product are needed.</p>1 aBishwas, Mousumi, Sen1 aDas, Raja1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/large-increase-energy-product-fe3se4-fe-site-doping-001810nas a2200277   4500008004100000022001400041245010700055210006900162260007700231300001400308490000700322520084200329653001501171653001501186653002401201653001801225653002201243100002401265700001901289700001401308700002001322700003001342700001601372700002401388856012001412       2014                        eng d  a1439-423500aLarge magnetocaloric effect, moment, and coercivity enhancement after coating Ni nanoparticles with Ag0 aLarge magnetocaloric effect moment and coercivity enhancement af  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcJUN  a1619-16230 v153 a<p>We observe a large magnetocaloric effect in monodisperse Ni and NicoreAgshell nanoparticles in the superparamagnetic region. The organically passivated Ni nanospheres show a large magnetic entropy change of 0.9 J kg(-1)K for a 3 T magnetic field change. In comparison to the surfactant-coated Ni nanoparticles, the NicoreAgshell nanoparticles show an enhanced coercivity, magnetization, and magnetocaloric effect (1.3 kgK for a 3 T magnetic field change). The coercivity at 10 K increases from 360 Oe for Ni nanoparticles to nearly 610 Oe for NicoreAgshell particles. This large enhancement is attributed to the enhanced inter-particle interaction, which is mediated by the metallic shell, over the relatively weaker dipolar interaction in the surfactant-coated Ni nanoparticles, and to modification of the surface spin structure.</p>10aanisotropy10acore-shell10amagnetic properties10aNanoparticles10asuperparamagnetic1 aSrinath, Sanyadanam1 aPoddar, Pankaj1 aDas, Raja1 aSidhaye, Deepti1 aPrasad, Bhagavatula L. V.1 aGass, James1 aSrikanth, Hariharan  uhttps://library.ncl.res.in/content/large-magnetocaloric-effect-moment-and-coercivity-enhancement-after-coating-ni-001181nas a2200193   4500008004100000022001400041245012300055210006900178260007100247300001200318490000700330520043100337100001900768700001400787700001700801700002000818700001800838856013100856       2014                        eng d  a1528-748300aLigand-free one-step synthesis of {001} faceted semiconducting BiOCl single crystals and their photocatalytic activity0 aLigandfree onestep synthesis of 001 faceted semiconducting BiOCl  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN  a236-2390 v143 a<p>Herein, we report one-step ligand-free hydrothermal synthesis of predominantly {001}-faceted micron-sized single crystals of bismuth oxychloride (BiOCl). The structural chlorine is obtained by in situ generation of chloride ions. From Raman spectra, we could resolve the E-g transition. Photocatalytic activity of as-synthesized crystals showed 78% degradation of RhB dye under a xenon source after 120 min of exposure.</p>1 aBiswas, Anupam1 aDas, Raja1 aDey, Chandan1 aBanerjee, Rahul1 aPoddar, Panka  uhttps://library.ncl.res.in/content/ligand-free-one-step-synthesis-001-faceted-semiconducting-biocl-single-crystals-and-their-002370nas a2200337   4500008004100000022001400041245013200055210006900187260005700256300000800313490000600321520116600327653002301493653002301516653002701539653001901566653002401585653002001609653001401629653001401643100003201657700001901689700001401708700002901722700003301751700002701784700003401811700003001845700002701875856013001902       2014                        eng d  a1556-276X00aModification of crystal anisotropy and enhancement of magnetic moment of Co-doped SnO2 thin films annealed under magnetic field0 aModification of crystal anisotropy and enhancement of magnetic m  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcNOV  a6350 v93 a<p>Co-doped SnO2 thin films were grown by sputtering technique on SiO2/Si(001) substrates at room temperature, and then, thermal treatments with and without an applied magnetic field (H-TT) were performed in vacuum at 600 degrees C for 20 min. H-TT was applied parallel and perpendicular to the substrate surface. Magnetic M(H) measurements reveal the coexistence of a strong antiferromagnetic (AFM) signal and a ferromagnetic (FM) component. The AFM component has a N,el temperature higher than room temperature, the spin axis lies parallel to the substrate surface, and the highest magnetic moment m =7 mu(B)/Co at. is obtained when H-TT is applied parallel to the substrate surface. Our results show an enhancement of FM moment per Co+2 from 0.06 to 0.42 mu(B)/Co at. for the sample on which H-TT was applied perpendicular to the surface. The FM order is attributed to the coupling of Co+2 ions through electrons trapped at the site of oxygen vacancies, as described by the bound magnetic polaron model. Our results suggest that FM order is aligned along [101] direction of Co-doped SnO2 nanocrystals, which is proposed to be the easy magnetization axis.</p>10aAntiferromagnetism10aCrystal anisotropy10aDiluted magnetic oxide10aFerromagnetism10aMagnetic anisotropy10aMagnetic moment10aSpin axis10athin film1 aLoya-Mancilla, Sagrario, M.1 aPoddar, Pankaj1 aDas, Raja1 aPonce, Hilda, E. Esparza1 aTempleton-Olivares, Ivan, L.1 aSolis-Canto, Oscar, O.1 aOrnelas-Gutierrez, Carlos, E.1 aEspinosa-Magaa, Francisco1 aOlive-Mendez, Sion, F.  uhttps://library.ncl.res.in/content/modification-crystal-anisotropy-and-enhancement-magnetic-moment-co-doped-sno2-thin-films-001913nas a2200157   4500008004100000022001400041245017300055210006900228260011000297300001600407490000600423520116900429100001401598700001901612856012401631       2014                        eng d  a2046-206900aObservation of exchange bias below incommensurate antiferromagnetic (ICAFM) to canted A-type antiferromagnetic (cAAFM) transition in nanocrystalline orthorhombic EuMnO30 aObservation of exchange bias below incommensurate antiferromagne  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a10614-106180 v43 a<p>Detailed ac and dc magnetic properties of orthorhombic EuMnO3 were studied using a nanocrystalline powder sample. Orthorhombic EuMnO3 nanoparticles of 45 nm average size were synthesised using a hydrothermal method. Zero field cooled (ZFC) and field cooled (FC) magnetisation shows anomalies at similar to 53, 44 and 24 K attributed to paramagnetic (PM) to an incommensurate antiferromagnetic phase (ICAFM), ICAFM to a canted A-type antiferromagnetic order (cAAFM) and spin reorientation transitions, respectively. No indication of a PM to ICAFM transition was observed in either the real or imaginary part of ac magnetisation. The real part of the ac magnetisation curve showed a peak at similar to 24.7 K and anomalies at similar to 46.8 and 21.8 K were observed in the imaginary part of ac magnetisation. Reduction in the width of the thermal hysteresis between the field cooling and heating magnetisation curve was observed with the nanocrystallites (similar to 1 K) compared with the bulk phase (similar to 3 K) EuMnO3. Isothermal magnetisation showed a large value of the exchange bias (2799 Oe at 3 K) below the ICAFM to cAAFM transition temperature.</p>1 aDas, Raja1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/observation-exchange-bias-below-incommensurate-antiferromagnetic-icafm-canted-type-002361nas a2200265   4500008004100000022001400041245011400055210006900169260009900238300001200337490000600349520141000355653001901765653002301784653002001807653001201827653001801839100001501857700002201872700001401894700002201908700001901930700002201949856012401971       2015                        eng d  a1998-012400aSelf-assembled vertically aligned gold nanorod super-lattices for ultra-high sensitive detection of molecules0 aSelfassembled vertically aligned gold nanorod superlattices for   aTSINGHUA UNIV, RM A703, XUEYAN BLDG, BEIJING, 10084, PEOPLES R CHINAbTSINGHUA UNIV PRESScMAR  a907-9190 v83 a<p>We show that self-assembled vertically aligned gold nanorod (VA-GNRs) superlattices can serve as probes or substrates for ultra-high sensitive detection of various molecules. D-glucose and 2,4,6-trinitrotoluene (TNT) have been chosen as model systems due to their very low Raman cross-sections (5.6 x 10(-30) cm(2).molecule(-1).sr(-1) for D-glucose and 4.9 x 10(-31) cm(2). molecule(-1).sr(-1) for TNT) to show that the VA-GNR superlattice assembly offers as low as yoctomole sensitivity. Our experiment on mixed samples of bovine serum albumin (BSA) and D-glucose solutions demonstrate sensitivity for the latter, and the possible extension to real samples. Self-assembled superlattices of VA-GNRs were achieved on a silicon wafer by depositing a drop of solvent containing the GNRs and subsequent solvent evaporation in ambient conditions. An additional advantage of the VA-GNR monolayers is their extremely high reproducible morphology accompanied by ultrahigh sensitivity which will be useful in many fields where a very small amount of analyte is available. Moreover the assembly can be reused a number of times after removing the already present molecules. The method of obtaining VA-GNRs is simple, inexpensive and reproducible. With the help of simulations of monolayers and multilayers it has been shown that superlattices can achieve better sensitivity than monolayer assembly of VA-GNRs.</p>10aNanostructures10aRaman spectroscopy10aself-assemblies10asensors10asuperlattices1 aApte, Amey1 aBhaskar, Prashant1 aDas, Raja1 aChaturvedi, Smita1 aPoddar, Pankaj1 aKulkarni, Sulabha  uhttps://library.ncl.res.in/content/self-assembled-vertically-aligned-gold-nanorod-super-lattices-ultra-high-sensitive-001876nas a2200181   4500008004100000022001400041245012100055210006900176260011000245300001600355490000600371520110900377100002201486700001401508700001901522700002201541856013101563       2015                        eng d  a2046-206900aTunable band gap and coercivity of bismuth ferrite-polyaniline core-shell nanoparticles: the role of shell thickness0 aTunable band gap and coercivity of bismuth ferritepolyaniline co  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a23563-235680 v53 a<p>We report a tunable band gap of bismuth ferrite-polyaniline core-shell nanoparticles from 2.24 to 1.98 eV and the variation of coercivity from 118 to 100 Oe, by varying the thickness of the polyaniline shell. Bismuth ferrite nanoparticles were synthesized via a chemical route and coating of polyaniline was achieved by a double surfactant layer technique. Coating of polyaniline introduced oxygen vacancies, local distortions and microstrains in the bismuth ferrite lattice which resulted in a change in the Fe-O-Fe bond angle of the bismuth ferrite lattice. This is confirmed with structural analysis tools i.e. X-ray Diffraction, Fourier Transform Infrared Spectroscopy and Raman spectroscopy. Moreover, the absorption of light around 600 nm is increased and photoluminescence emission around 430 nm is decreased, as the thickness of shell is increased, which also indicates the changes in optical properties due to variation in shell thickness. Thus tunability of the band gap and coercivity is achieved as a function of shell thickness in bismuth ferrite-polyaniline core-shell nanoparticles.</p>1 aChaturvedi, Smita1 aDas, Raja1 aPoddar, Pankaj1 aKulkarni, Sulabha  uhttps://library.ncl.res.in/content/tunable-band-gap-and-coercivity-bismuth-ferrite-polyaniline-core-shell-nanoparticles-role-002812nas a2200217   4500008004100000245016800041210006900209260000800278300001200286490000600298520200000304100001902304700002302323700001402346700002102360700001602381700002102397700002502418700001902443856013202462       2017                        eng d00aOxidant mediated one-step complete conversion of multi-walled carbon nanotubes to graphene quantum dots and their bioactivity against mammalian and bacterial cells0 aOxidant mediated onestep complete conversion of multiwalled carb  cJAN  a785-7960 v53 aIt is essential for any antibacterial agent (for clinical applications) that it should have high and selective toxicity towards bacterial cells only, and should not affect the human cells at the concentration used. Graphene quantum dots (GQDs) have emerged as a potential candidate for biomedical applications. However, a simple, low cost, safe, easy to execute, one-step synthesis of uniform and monodispersed GQDs with selective toxicity towards bacterial cells rather than mammalian cells is difficult to achieve. Herein, we have reported a one-step, low-cost, aqueous-phase, simple approach for the complete conversion of multi-walled carbon nanotubes into water-dispersible GQDs with an average size of similar to 3 nm using sodium bismuthate (NaBiO3) as a strong oxidant. The cyclic voltammetry and X-ray photoelectron spectroscopy results indicated that the as-synthesized GQDs suspension possess almost negligible amounts of metallic impurities. The cytotoxicity studies of GQDs against mammalian NIH 3T3 (mouse embryo fibroblast cells) and HEK 293T (human embryonic kidney cells) cells showed that the as-synthesized GQDs were non-cytotoxic up to the concentration of similar to 200 mu g mL(-1). The antimicrobial study shows that the synthesized GQDs have high and selective toxicity towards bacterial cells with a minimum inhibitory concentration of similar to 256 mu g mL(-1) for E. coli and B. subtilis and similar to 512 mu g mL(-1) for P. aeruginosa and S. aureus. The scanning electron microscopy and atomic force microscopy images show extensive cell damage via the perturbation of bacterial cell walls, which was consistent with the enhancement of reactive oxygen species production by almost two times in the bacterial cells upon incubation with similar to 256 mu g mL(-1) GQDs. Our study suggested that the as-synthesized GQDs can be used as a potential candidate for clinical applications as they possess high toxicity to bacterial cells and low toxicity to mammalian cells.1 aBiswas, Anupam1 aKhandelwal, Puneet1 aDas, Raja1 aSalunke, Gayatri1 aAlam, Aftab1 aGhorai, Suvankar1 aChattopadhyay, Samit1 aPoddar, Pankaj  uhttps://library.ncl.res.in/content/oxidant-mediated-one-step-complete-conversion-multi-walled-carbon-nanotubes-graphene-quantum