01433nas a2200241   4500008004100000022001400041245004900055210004900104260006900153300001200222490000800234520072900242653001200971653001300983653002400996653001801020653001101038100001701049700001401066700001601080700001201096856008301108       2005                        eng d  a0921-510700aCoprecipitation technique to prepare BaNb2O60 aCoprecipitation technique to prepare BaNb2O6  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAR  a169-1710 v1173 a<p>A mixture of ammonium oxalate and ammonium hydroxide was used to coprecipitate barium and niobium ions as barium oxalate and niobium hydroxide under basic conditions. This precursor on calcination at 750degreesC yielded BaNb2O6 ceramics. This is a much lower temperature as compared to that prepared by traditional solid-state method (1000degreesC), as reported for the formation of BaNb2O6. Transmission electron microscope (TEM) investigations revealed that the average particle size is 100 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found to be 1100. The ferroelectric hysteresis loop parameters of these samples were also studied. (C) 2004 Elsevier B.V. All rights reserved.</p>10aAmmonia10aCeramics10aElectron microscopy10aniobium oxide10aOxides1 aNatarajan, N1 aSamuel, V1 aPasricha, R1 aRavi, V  uhttps://library.ncl.res.in/content/coprecipitation-technique-prepare-banb2o6-001665nas a2200241   4500008004100000022001400041245011200055210006900167260007300236300001200309490000600321520081500327653000801142653003901150653001901189653000801208100002001216700001401236700001601250700001401266700002401280856011901304       2005                        eng d  a1567-173900aDNA and PNA as templates for building nanoassemblies via electrostatic complexation with gold nanoparticles0 aDNA and PNA as templates for building nanoassemblies via electro  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a102-1070 v53 a<p>Organisation of nanoparticles on structurally well-defined templates is a first step towards creating nanomachines. In this respect, nucleic acids are ideal structural templates and a variety of secondary structures realizable from DNA/RNA - e.g., duplexes, hairpins, triplexes, cruciforms, tetraplexes can be exploited to engineer nanoparticle organization at will. We have used oligonucleotides and their analogues such as phosphorothioates and peptide nucleic acids to electrostatically encapsulate cationic-capped gold nanoparticles. This article describes synthesis and characterization of DNA/PNA-gold nanoparticle composites using TEM and UV-T-m techniques. These types of assemblies may have potential for creating nanowires and lithographic circuits. (C) 2004 Elsevier B.V. All rights reserved.</p>10aDNA10aDNA-gold nanoparticle interactions10ananoassemblies10aPNA1 aGourishankar, A1 aShukla, S1 aPasricha, R1 aSastry, M1 aGanesh, Krishna, N.  uhttps://library.ncl.res.in/content/dna-and-pna-templates-building-nanoassemblies-electrostatic-complexation-gold-001539nas a2200241   4500008004100000022001400041245008100055210006900136260010500205300001200310490000700322520070400329653001301033653002301046653002401069653002101093653001101114100002001125700001401145700001601159700001201175856011001187       2005                        eng d  a0250-470700aPreparation of nanocrystalline ferroelectric BaNb(2)O6 by citrate gel method0 aPreparation of nanocrystalline ferroelectric BaNb2O6 by citrate   aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACADEMY SCIENCEScAPR  a121-1230 v283 a<p>A gel was formed when a aqueous solution of BaCl2, NbF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 600 degrees C yielded the nano crystallites of BaNb2O6, as confirmed by X-ray diffraction study (XRD). This is a much lower temperature as compared to that prepared by traditional solid state method (1000 degrees C) as reported for the formation of BaNb2O6. Transmission electron microscopic. (TEM) investigations revealed that the average particle size is 50 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found to be 1000. The ferroelectric hysteresis loop parameters of these samples were also studied.</p>10aCeramics10aChemical synthesis10aelectronic material10aferroelectricity10aOxides1 aGaikwad, S., P.1 aSamuel, V1 aPasricha, R1 aRavi, V  uhttps://library.ncl.res.in/content/preparation-nanocrystalline-ferroelectric-banb2o6-citrate-gel-method-001583nas a2200217   4500008004100000022001400041245007900055210006900134260010000203300001200303490000700315520077500322653002601097653002401123653002901147653003501176100002001211700001601231700001201247856010601259       2005                        eng d  a0272-884200aPreparation of nanocrystalline ferroelectric CaBi2Ta2O9 by the urea method0 aPreparation of nanocrystalline ferroelectric CaBi2Ta2O9 by the u  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcJAN   a773-7750 v313 a<p>A precipitate was formed when a aqueous solution of CaCl2, BiCl3, TaF5 and urea in stoichiometric ratio (total metal cations to urea ratio is 5) is heated on a water bath. This precipitate on decomposition at 600 degrees C yielded the nanocrystallites of ternary oxide CaBi2Ta2O9 (CBT) as confirmed by X-ray diffraction (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). Ferroelectric hysteresis loop parameters such as remnant polarization (P-r) and coercive field (E-C) were also determined. TEM investigations revealed that the average particle size of the polycrystalline powder is 70 nm. The room temperature dielectric constant was found to be 110. (c) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved.</p>10adielectric properties10aElectron microscopy10aferroelectric properties10apowders : chemical preparation1 aGaikwad, S., P.1 aPasricha, R1 aRavi, V  uhttps://library.ncl.res.in/content/preparation-nanocrystalline-ferroelectric-cabi2ta2o9-urea-method-001418nas a2200205   4500008004100000022001400041245008100055210006900136260006900205300001200274490000800286520070600294653001201000653001601012653002401028100002001052700001601072700001201088856011201100       2005                        eng d  a0921-510700aPreparation of nanocrystalline ferroelectric CaBi2TaO9 by citrate gel method0 aPreparation of nanocrystalline ferroelectric CaBi2TaO9 by citrat  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAR  a159-1610 v1173 a<p>A gel was formed when an aqueous solution of CaCl2, BiCl3, TaF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 600degreesC yielded the nano-crystallites of ternary oxide, CaBi2Ta2O9 (CBT) as confirmed by X-ray diffraction study (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). Ferroelectric hysteresis loop parameters such as remnant polarization (P-r) and coercive field (E-C) are also determined. TEM investigations revealed that the average particle size of the polycrystalline powder is 40 nm. The room temperature dielectric constant was found to be 90. (C) 2004 Elsevier B.V All rights reserved.</p>10aBismuth10adiffraction10aElectron microscopy1 aGaikwad, S., P.1 aPasricha, R1 aRavi, V  uhttps://library.ncl.res.in/content/preparation-nanocrystalline-ferroelectric-cabi2tao9-citrate-gel-method-001196nas a2200217   4500008004100000022001400041245006500055210006500120260007300185300001400258490000700272520047900279653001600758653002400774653002200798653001200820653002200832100001600854700001200870856009600882       2005                        eng d  a0167-577X00aPreparation of nanocrystalline MgNb2O6 by citrate gel method0 aPreparation of nanocrystalline MgNb2O6 by citrate gel method  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL  a2146-21480 v593 a<p>A gel was formed when a aqueous solution of Mg(NO3)(2), NbF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 700 degrees C produced the fine crystallites of ternary oxide, MgNb2O6 (MN). The formation of MN phase and lattice parameters were determined by the powder X-ray diffraction (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). (c) 2005 Elsevier B.V. All rights reserved.</p>10aCitrate gel10aElectron microscopy10amagnesium niobate10apowders10aX-ray diffraction1 aPasricha, R1 aRavi, V  uhttps://library.ncl.res.in/content/preparation-nanocrystalline-mgnb2o6-citrate-gel-method-002534nas a2200277   4500008004100000022001400041245007200055210006900127260009500196300001400291490000600305520159800311653003201909653001501941653003101956653001801987653002102005653002402026653001502050100001902065700002002084700001602104700001602120700001402136856010602150       2005                        eng d  a1533-488000aSynthesis of CdS and alloyed CdMnS nanocrystals using aqueous foams0 aSynthesis of CdS and alloyed CdMnS nanocrystals using aqueous fo  a25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USAbAMER SCIENTIFIC PUBLISHERScDEC  a2144-21540 v53 a<p>Certain surfactant-stabilized aqueous foams provide a potentially efficient and simple chemical route for the synthesis of various nanomaterials with controllable structure, size, and shape. In the present work, a one-step process for the synthesis of CdS and Cdl(1-x)Mn(x)S (0 &lt; x &lt; 10) nanocrystals has been described. Aqueous CdCl2 and the aerosol-OT solutions are homogeneously mixed together and thereafter, nitrogen is bubbled through this solution to produce stable aqueous foam. After drainage of the foam, the freestanding dry foam consisting of cadmium cations electrostatically complexed with the anionic aerosol-OT molecules at the liquid-gas interface is treated with H2S vapor. The foam turns yellowish-orange and collapses, in the process yielding CdS nanoclusters of variable morphology. This morphology variation is appropriately attributed to growth of the CdS as well as alloyed Cd1-xMnxS nanoparticles in different regions of the foam contributing to the varying topological structure. Optical absorption spectra of both CdS and Cd1-xMnxS nanoparticles clearly show a well-defined exciton absorption feature around 450 nm due to quantum confinement effects. The interesting band edge emission characteristics of these AOT-capped CdS and Cd1-xMnxS nanoparticles produced in the foam are discussed with respect to their size and shape. Particular interest in the present novel aqueous foam approach arises due to the fact that the cubic zincblende CdS and alloyed Cd1-xMnxS nanocrystals could easily be obtained even under ambient experimental conditions itself.</p>10aabsorption and fluorescence10aaerosol-OT10aalloyed CdMnS nanocrystals10aaqueous foams10aCdS nanoclusters10aquantum confinement10azincblende1 aKumar, Senthil1 aKasture, Manasi1 aRaghavan, U1 aPasricha, R1 aSastry, M  uhttps://library.ncl.res.in/content/synthesis-cds-and-alloyed-cdmns-nanocrystals-using-aqueous-foams-001326nas a2200229   4500008004100000022001400041245004000055210004000095260009900135300001200234490000700246520063900253653002500892653002400917653001200941653000900953653001800962100001400980700001600994700001201010856007401022       2005                        eng d  a0272-884200aSynthesis of nanocrystalline rutile0 aSynthesis of nanocrystalline rutile  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcJAN  a555-5570 v313 a<p>Nanocrystalline titanium dioxide (TiO2) in the rutile phase has been obtained by homogeneous precipitation using urea and TiOCl2. A mixture of urea and TiOCl2 is heated on a hot water bath at 65-75 degrees C to precipitate rutile powders. X-ray diffraction (XRD) studies on these oven-dried powders indicated the formation of single-phase rutile. Raman scattering experiments were also performed to confirm the formation of the rutile phase. Transmission electron microscopy (TEM) investigations revealed the average particle size of these powders to be 40 nm. (c) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved.</p>10achemical preparation10aElectron microscopy10apowders10aTiO210aX-ray methods1 aSamuel, V1 aPasricha, R1 aRavi, V  uhttps://library.ncl.res.in/content/synthesis-nanocrystalline-rutile-001244nas a2200205   4500008004100000022001400041245005500055210005300110260006900163300001000232490000700242520060800249653001300857653002400870653002100894653001100915100001600926700001200942856008400954       2005                        eng d  a0254-058400aSynthesis of Sr0.5Ba0.5Nb2O6 by citrate gel method0 aSynthesis of Sr05Ba05Nb2O6 by citrate gel method  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcNOV  a34-360 v943 a<p>A gel was formed when an aqueous solution of BaCl2, SrCl2, NbF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 700 degrees C yielded the nanocrystallites of ternary oxide, Sr0.5Ba0.5Nb2O6 (SBN) as confirmed by X-ray diffraction study (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). The room temperature dielectric constant at I kHz is 1000. The ferroelectric hysteresis loop parameters of these samples were also studied by a home built Sawyer-Tower circuit. (c) 2005 Elsevier B.V. All rights reserved.</p>10aCeramics10aElectron microscopy10aferroelectricity10aOxides1 aPasricha, R1 aRavi, V  uhttps://library.ncl.res.in/content/synthesis-sr05ba05nb2o6-citrate-gel-method-001826nas a2200169   4500008004100000022001400041245012900055210006900184260007100253300001600324490000800340520113300348100001601481700001301497700001401510856013201524       2005                        eng d  a1520-610600aTransmetalation reaction between hydrophobic silver nanoparticles and aqueous chloroaurate ions at the air - Water interface0 aTransmetalation reaction between hydrophobic silver nanoparticle  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a19620-196260 v1093 a<p>The transmetalation reaction between a sacrificial nanoparticle and more noble metal ions in solution has emerged as a novel method for creating unique hollow and bimetallic nanostructures. In this report, we investigate the possibility of carrying out the transmetalation reaction between hydrophobic silver nanoparticles assembled and constrained at the air-water interface and subphase gold ions. We observe that facile reduction of the subphase gold ions by the sacrificial silver nanoparticles occurs resulting in the formation of elongated gold nanostructures that appear to cross-link the sacrificial silver particles. This transmetalation reaction may be modulated by the insertion of an electrostatic barrier in the form of an ionizable lipid monolayer between the silver nanoparticles and the aqueous gold ions that impacts the gold nanoparticle assembly. Transmetalation reactions between nanoparticles constrained into a close-packed structure and appropriate metal ions could lead to a new strategy for metallic cross-linking of nanoparticles and generation of coatings with promising optoelectonic behavior.</p>1 aPasricha, R1 aSwami, A1 aSastry, M  uhttps://library.ncl.res.in/content/transmetalation-reaction-between-hydrophobic-silver-nanoparticles-and-aqueous-chloroaurate-0