02391nas a2200241 4500008004100000022001400041245006900055210006500124260007300189300001200262490000700274520154300281653002601824653002201850653003901872653003501911653002301946100002401969700001701993700002302010700002002033856009602053 2005 eng d a0927-024800aInfluence of process pressure on HW-CVD deposited a-Si : H films0 aInfluence of process pressure on HWCVD deposited aSi H films aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a301-3120 v853 a

Hydrogenated amorphous silicon (a-Si:H) films were deposited using pure silane (SiH4) without hydrogen dilution by hot wire chemical vapor deposition (HW-CVD) technique. The electrical, optical, and structural properties of these films are systematically studied as a function of process pressure (P-r). The device quality a-Si:H films with a photosensitivity > 10(5) were deposited at a deposition rate >40 Angstrom/s at low process pressure. However, a-Si:H films deposited at higher process pressures show degradation in their electrical and structural properties. The FTIR spectroscopic analysis showed that a-Si:H films deposited at low process pressure contain hydrogen mainly in mono-hydrogen (Si-H) configuration whereas films deposited at higher process pressure have hydrogen in di-hydrogen (Si-H-2) or poly hydrogen (SiH2)(n) complexes. The hydrogen content (C-H) in the films was found to be less than 4 at.% over the entire range of process pressure studied. This indicates that the growth of a-Si:H films is mainly from the atomic species (Si and H) evaporated from the hot filament and hydrogen gets incorporated in the film via gas-phase reactions and substrate gas interactions. The band gap, however was found similar to1.71 eV or much higher. We attribute high band gap at low hydrogen content may be due to presence of microvoids. Raman spectroscopic analysis showed increase in structural disorder and Rayleigh scattering with increase in the process pressure. (C) 2004 Elsevier B.V. All rights reserved.

10aElectrical properties10aFTIR spectroscopy10ahot wire chemical vapor deposition10ahydrogenated amorphous silicon10aRaman spectroscopy1 aJadkar, Sandesh, R.1 aSali, J., V.1 aKshirsagar, S., T.1 aTakwale, M., G. uhttps://library.ncl.res.in/content/influence-process-pressure-hw-cvd-deposited-si-h-films-001884nas a2200253 4500008004100000022001400041245011800055210006900173260007300242300001200315490000800327520094000335653002301275653002301298653002701321653002301348653002101371653002401392100001501416700001901431700002401450700002801474856012801502 2006 eng d a0926-860X00aTransesterification of cyclic carbonates with methanol at ambient conditions over tungstate-based solid catalysts0 aTransesterification of cyclic carbonates with methanol at ambien aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a108-1140 v3123 a

Dimethyl carbonate synthesis with 80 mol% yield is achieved through transesterification of ethylene carbonate with methanol at ambient conditions (RT and atmospheric pressure) using alkali and alkaline-earth tungstates as solid catalysts. The catalysts are efficient even at the sub-ambient temperatures. Reactions under CO2 pressure indicate that CO2 atmosphere retards the transesterification reaction completely below 100 degrees C. Experimental conditions of 150 degrees C and 3.4 MPa CO2 pressure are required to obtain maximum DMC yield of 71 mol%. Synthesis of DMC by one-pot synthesis using epoxide, CO2 and methanol is not as effective as that by two-step method with the present catalyst system. Raman and IR spectra of methanol-interacting tungstates indicate the formation of a methoxide ion species adsorbed at the catalyst surface as one possible reaction intermediates. (C) 2006 Elsevier B.V. All rights reserved.

10aDimethyl carbonate10aethylene carbonate10aheterogeneous catalyst10aRaman spectroscopy10asodium tungstate10atransesterification1 aSankar, M.1 aNair, Madhavan1 aMurty, K., V. G. K.1 aManikandan, Palanichamy uhttps://library.ncl.res.in/content/transesterification-cyclic-carbonates-methanol-ambient-conditions-over-tungstate-based-001844nas a2200241 4500008004100000022001400041245008600055210006900141260010200210300001200312490000700324520095100331653002101282653003101303653002301334653003301357653001501390100002001405700002001425700002001445700002001465856011701485 2010 eng d a0304-428900aMonitoring structural defects and crystallinity of carbon nanotubes in thin films0 aMonitoring structural defects and crystallinity of carbon nanotu aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScMAR a447-4550 v743 a

We report the influence of catalyst formulation and reaction temperature on the formation of carbon nanotube (CNT) thin films by the chemical vapour deposition (CVD) method. Thin films of CNTs were grown on Fe-Mo/Al(2)O(3)-coated silicon wafer by thermal decomposition of methane at different temperatures ranging from 800 to 1000A degrees C. The electron microscopic investigations, SEM as well as HRTEM, of the as-grown CNT thin films revealed the growth of uniform multi-walled CNTs in abundance. The intensity ratio of D-band to G-band and FWHM of G-band through Raman measurements clearly indicated the dependency of structural defects and crystallinity of CNTs in thin films on the catalyst formulation and CVD growth temperature. The results suggest that thin films of multi-walled CNTs with negligible amount of defects in the nanotube structure and very high crystallinity can be obtained by thermal CVD process at 925A degrees C.

10aCarbon nanotubes10achemical vapour deposition10aRaman spectroscopy10ascanning electron microscopy10aThin films1 aMahajan, S., S.1 aBambole, M., D.1 aGokhale, S., P.1 aGaikwad, A., B. uhttps://library.ncl.res.in/content/monitoring-structural-defects-and-crystallinity-carbon-nanotubes-thin-films-002313nas a2200265 4500008004100000022001400041245011400055210006900169260005700238300001200295490000700307520138000314653002301694653001501717653000901732653002701741653002301768100002001791700002301811700002401834700001801858700002301876700002301899856012501922 2013 eng d a0361-523500aSynthesis of low coercive BaFe12O19 hexaferrite for microwave applications in low-temperature cofired ceramic0 aSynthesis of low coercive BaFe12O19 hexaferrite for microwave ap a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcAPR a761-7680 v423 a

Polycrystalline M-type barium hexaferrite (BaFe12O19) samples have been synthesized by solution combustion route at different pH and calcination conditions in order to reduce the coercivity for microwave applications in low-temperature cofired ceramic (LTCC) substrates. Structural, morphological, and magnetic properties of BaFe12O19 were studied by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy, vibrating sample magnetometry (VSM), and Mossbauer spectroscopy. The formation of a single-phase hexagonal structure was confirmed by XRD. The Raman spectra reveal all characteristic peaks of BaFe12O19, illustrating the phase purity and crystal lattice symmetry of the synthesized material. Mossbauer spectra illustrate the existence of Fe3+ cations at all five crystallographic lattice sites. The microstructural features observed by FESEM disclose the growth of nanoregime particles into hexagonal platelet particles after calcination at temperatures from 800A degrees C to 1200A degrees C. The VSM results show a lower coercivity (1350 Oe to 3500 Oe) together with reasonably high saturation magnetization (55 emu/g to 60 emu/g) and a high bulk resistivity (> 10(9) Omega-cm) at room temperature. The dependence of magnetic and electrical properties on the preparation and processing conditions is also discussed.

10aBarium hexaferrite10acoercivity10aLTCC10aMossbauer spectroscopy10aRaman spectroscopy1 aRane, Vivek, A.1 aMeena, Sher, Singh1 aGokhale, Suresh, P.1 aYusuf, S., M.1 aPhatak, Girish, J.1 aDate, Sadgopal, K. uhttps://library.ncl.res.in/content/synthesis-low-coercive-bafe12o19-hexaferrite-microwave-applications-low-temperature-001612nas a2200217 4500008004100000022001400041245006000055210005900115260007100174300001400245490000600259520089400265653002201159653002201181653002301203653001901226653000801245100002301253700002401276856009401300 2014 eng d a1944-824400aTemperature Dependent Phonon Shifts in Single-Layer WS20 aTemperature Dependent Phonon Shifts in SingleLayer WS2 a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN a1158-11630 v63 a

Atomically thin two-dimensional tungsten disulfide (WS2) sheets have attracted much attention due to their potential for future nanoelectronic device applications. We report first experimental investigation on temperature dependent Raman spectra of single-layer WS2 prepared using micromechanical exfoliation. Our temperature dependent Raman spectroscopy results shows that the E-2g(1) and A(1g) modes of single-layer WS2 soften as temperature increases from 77 to 623 K. The calculated temperature coefficients of the frequencies of 2LA(M), E-2g(1), A(1g), and A(1g)(M) + LA(M) modes of single-layer WS2 were observed to be -0.008, -0.006, -0.006, and -0.01 cm(-1) K-1, respectively. The results were explained in terms of a double resonance process which is active in atomically thin nanosheet. This process can also be largely applicable in other emerging single-layer materials.

10alayered materials10aphonon vibrations10aRaman spectroscopy10athermal effect10aWS21 aThripuranthaka, M.1 aLate, Dattatray, J. uhttps://library.ncl.res.in/content/temperature-dependent-phonon-shifts-single-layer-ws2-002225nas a2200265 4500008004100000022001400041245013500055210006900190260008100259300001100340490000700351520123800358653002301596653001701619653002501636100002001661700001801681700002401699700002901723700002101752700002001773700002401793700001901817856012301836 2015 eng d a0953-898400aCombined experimental and theoretical study of the structural, electronic and vibrational properties of bulk and few-layer Td-WTe20 aCombined experimental and theoretical study of the structural el aTEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLANDbIOP PUBLISHING LTDcJUL a2854010 v273 a

The recent discovery of non-saturating giant positive magnetoresistance has aroused much interest in Td-WTe2. We have investigated structural, electronic and vibrational properties of bulk and few-layer Td-WTe2 experimentally and theoretically. Spin-orbit coupling is found to govern the semi-metallic character of Td-WTe2 and its structural link with the metallic 1 T form provides an understanding of its structural stability. There is a metal-to-insulator switch-over in the electrical conductivity and a change in the sign of the Seebeck coefficient around 373 K. Lattice vibrations of Td-WTe2 have been analyzed using first-principles calculations. Out of the 33 possible zone-center Raman active modes, five distinct Raman bands are observed around 112, 118, 134, 165 and 212 cm(-1) in bulk Td-WTe2. Based on symmetry analysis and calculated Raman tensors, we assign the intense bands at 165 cm(-1) and 212 cm(-1) to the A(1)' and A(1)'' modes, respectively. Most of the Raman bands stiffen with decreasing thickness, and the ratio of the integrated intensities of the A(1)'' to A(1)' bands decreases in the few-layer sample, while all the bands soften in both the bulk and few-layer samples with increasing temperature.

10aRaman spectroscopy10aTd-structure10atungsten ditelluride1 aJana, Manoj, K.1 aSingh, Anjali1 aLate, Dattatray, J.1 aRajamathi, Catherine, R.1 aBiswas, Kanishka1 aFelser, Claudia1 aWaghmare, Umesh, V.1 aRao, C., N. R. uhttps://library.ncl.res.in/content/combined-experimental-and-theoretical-study-structural-electronic-and-vibrational-102361nas 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

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.

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-001609nas a2200265 4500008004100000022001400041245009900055210006900154260006400223300000700287490000600294520068100300653002200981653002201003653000901025653002201034653002301056100002301079700002501102700002301127700002201150700002401172700002301196856012401219 2015 eng d a1847-980400aStable field emission from layered MoS2 nanosheets in high vacuum and observation of 1/f noise0 aStable field emission from layered MoS2 nanosheets in high vacuu aJANEZA TRDINE 9, RIJEKA, 51000, CROATIAbINTECH EUROPEcAPR a100 v53 a

Field emission and current noise of hydrothermally synthesized MoS2 nanosheets are investigated in ultra-high-vacuum and industrially suited high-vacuum conditions. The study reveals that the emission turn-on field is pressure dependent. Moreover, the MoS2 nanosheets exhibit more stable field-electron emission in high-vacuum than in ultra-high-vacuum conditions. The investigations on field-emission current fluctuations show features of 1/f-type noise in ultra-high-vacuum and high-vacuum conditions, attributed to adsorption and desorption processes. The post-field-emission results indicate the MoS2 nanosheets are a robust field emitter in high-vacuum conditions.

10aElectron emission10alayered materials10aMoS210aNoise measurement10aRaman spectroscopy1 aKashid, Ranjit, V.1 aJoag, Pracheetee, D.1 aThripuranthaka, M.1 aRout, Chandra, S.1 aLate, Dattatray, J.1 aMore, Mahendra, A. uhttps://library.ncl.res.in/content/stable-field-emission-layered-mos2-nanosheets-high-vacuum-and-observation-1f-noise-101832nas a2200205 4500008004100000022001400041245007000055210006900125260007100194300001400265490000600279520110600285653002101391653002201412653002201434653002301456653001901479100002401498856010401522 2015 eng d a1944-824400aTemperature dependent phonon shifts in few-layer black phosphorus0 aTemperature dependent phonon shifts in fewlayer black phosphorus a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR a5857-58620 v73 a

Atomically thin two-dimensional (2D) sheets of black phosphorus have attracted much attention due to their potential for future nanoelectronic and photonics device applications. Present investigations deal with the temperature dependent phonon shifts in a few-layer black phosphorus nanosheet sample prepared using micromechanical exfoliation on a 300 nm SiO2/Si substrate. The temperature dependent Raman spectroscopy experiments were carried out on a few-layer black phosphorus sample, which depicts softening of Ag-1 B-2g, and A(g)(2) modes as temperature increases from 77 to 673 K. The calculated temperature coefficients for Ag-1, B-2g, and A(g)(2) modes of the few-layer black phosphorus nanosheet sample were observed to be -0.01, -0.013, and -0.014 cm(-1) K-1, respectively. The temperature dependent softening modes of black phosphorus results were explained on the basis of a double resonance process which is more active in an atomically thin sample. This process can also be fundamentally pertinent in other promising and emerging 2D ultrathin layer and heterostructured materials.

10ablack phosphorus10alayered materials10aphonon vibrations10aRaman spectroscopy10athermal effect1 aLate, Dattatray, J. uhttps://library.ncl.res.in/content/temperature-dependent-phonon-shifts-few-layer-black-phosphorus-002554nas a2200325 4500008004100000022001400041245010200055210006900157260007100226300001600297490000600313520142000319653002201739653002201761653002301783653001901806653002101825653002001846100002201866700002301888700002001911700002201931700002001953700002301973700002401996700003102020700003002051700002402081856012302105 2015 eng d a1944-824400aTemperature-dependent raman spectroscopy of titanium trisulfide (TiS3) nanoribbons and nanosheets0 aTemperaturedependent raman spectroscopy of titanium trisulfide T a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a24185-241900 v73 a

Titanium trisulfide (TiS3) has recently attracted the interest of the 2D community because it presents a direct bandgap of similar to 1.0 eV, shows remarkable photoresponse, and has a predicted carrier mobility up to 10000 cm(2) V-1 s(-1). However, a study of the vibrational properties of TiS3, relevant to understanding the electron-phonon interaction that can be the main mechanism limiting the charge carrier mobility, is still lacking. In this work, we take the first steps to study the vibrational properties of TiS3 through temperature-dependent Raman spectroscopy measurements of TiS3 nanoribbons and nanosheets. Our investigation shows that all the Raman modes linearly soften (red shift) as the temperature increases from 88 to 570 K due to anharmonic vibrations of the lattice, which also includes contributions from the lattice thermal expansion. This softening with the temperature of the TiS3 modes is more pronounced than that observed in other 2D semiconductors, such as MoS2, MoSe2, WSe2, and black phosphorus (BP). This marked temperature dependence of the Raman spectra could be exploited to determine the temperature of TiS3 nanodevices by using Raman spectroscopy as a noninvasive and local thermal probe. Interestingly, the TiS3 nanosheets show a stronger temperature dependence of the Raman modes than the nanoribbons, which we attribute to lower interlayer coupling in the nanosheets.

10a2D semiconductors10alayered materials10aRaman spectroscopy10athermal effect10aTiS3 nanoribbons10aTiS3 nanosheets1 aPawbake, Amit, S.1 aIsland, Joshua, O.1 aFlores, Eduardo1 aAres, Jose, Ramon1 aSanchez, Carlos1 aFerrer, Isabel, J.1 aJadkar, Sandesh, R.1 avan der Zant, Herre, S. J.1 aCastellanos-Gomez, Andres1 aLate, Dattatray, J. uhttps://library.ncl.res.in/content/temperature-dependent-raman-spectroscopy-titanium-trisulfide-tis3-nanoribbons-and-001901nas a2200205 4500008004100000022001400041245007600055210006900131260000800200300001100208490000600219520124400225653002101469653001001490653002101500653002301521653001901544100002401563856010801587 2016 eng d a2352-940700aTemperature-dependent phonon shifts in atomically thin MoTe2 nanosheets0 aTemperaturedependent phonon shifts in atomically thin MoTe2 nano cDEC a98-1020 v53 a

The present investigations deal with temperature-dependent Raman spectroscopy of bi-layer and few-layer molybdenum telluride (MoTe2) nanosheets prepared by micromechanical exfoliation method on a 300 nm SiO2/Si substrate. The temperature-dependent Raman spectroscopy was carried out using 633 nm laser excitation over the wider temperature range of 123-523 K. The temperature-dependent study illustrates the softening of A(1g), E-2g(1), and B-2g modes as temperature increases from 123 K to 523 K. The calculated temperature coefficients for A(1g), E-2g(1) and B-2g modes of the bi-layer MoTe2, nanosheet sample were found to be -0.00911 cm(-1) K-1, -0.01297 cm(-1) K-1 and -0.0159 cm(-1) K-1,respectively. For few-layer MoTe2 nanosheet sample, the temperature coefficient values were found to be -0.0113 cm(-1) K-1 (A(1g)), -0.0129 cm(-1) K-1 (E-2g(1)) and -0.0149 cm(-1) K-1 (B-2g), respectively. The present work highlights the temperature-dependent lattice vibration consequence of 2D MoTe2 nanosheet, which can be fundamentally pertinent in other promising and emerging 2D ultrathin layer and heterostructured materials to be used in future optoelectronic and nanoelectronic devices. (C) 2016 Elsevier Ltd. All rights reserved.

10aLayered material10aMoTe210aPhonon vibration10aRaman spectroscopy10athermal effect1 aLate, Dattatray, J. uhttps://library.ncl.res.in/content/temperature-dependent-phonon-shifts-atomically-thin-mote2-nanosheets01833nas a2200277 4500008004100000245006500041210006200106260008800168520088700256653002801143653002401171653002301195653002101218653000801239100001701247700002301264700001901287700001801306700002101324700002401345700001701369700002001386700002701406700002501433856009701458 2017 eng d00aSolubility limits of ceria-zirconia-lanthana solid-solutions0 aSolubility limits of ceriazirconialanthana solidsolutions aJaipur, IndiabElsevier Science BV, PO BOX 211, 1000 AE Amsterdam, NetherlandscMAR3 a

We demonstrate, the solubility limits of Ceria-Zirconia-Lanthana (CZLa) solid-solutions with the increase in heat-treatment temperature from 600 degrees C to 1300 degrees C. CZLa nano-crystalline samples were successfully synthesized by EDTA-Citrate complex method and were characterized by Raman Spectroscopy (RS) and Transmission Electron Microscopy (TEM) analysis. With an increase in temperature, it is noticed that the solubility limit is decreased in CZLa system. At 600 degrees C, a very good solubility is observed in CZLa system and is confirmed from RS analysis. At higher heat-treatment temperatures (1000 and 1300 degrees C), with an increase in La content, Zr precipitated in the CZLa system and is confirmed from RS analysis. The reason for such kind of behavior in this CZLa system is clearly explained in this work. (C) 2017 Elsevier Ltd. All rights reserved.

10aCeria-Zirconia Lanthana10aEDTA-Citrate method10aRaman spectroscopy10asolubility limit10aXRD1 aAbbas, Zenab1 aSurendran, Mythili1 aAnjana, P., A.1 aJidev, P., K.1 aDasari, Harshini1 aNaidu, Sudhakar, N.1 aAnandhan, S.1 aBhat, Udaya, K.1 aBabu, Uday, Bhaskar G.1 aDasari, Hari, Prasad uhttps://library.ncl.res.in/content/solubility-limits-ceria-zirconia-lanthana-solid-solutions02134nas a2200277 4500008004100000022001200041245010700053210006900160260000900229300001200238490000700250520121100257653001301468653001801481653001101499653002801510653002301538100002201561700001901583700002501602700002401627700002701651700002601678700002401704856012801728 2018 eng d a925963500aTemperature and pressure dependent Raman spectroscopy of plasma treated multilayer graphene nanosheets0 aTemperature and pressure dependent Raman spectroscopy of plasma  cAPR  a146-1560 v843 a

Understanding of the fine structure at the atomic level and properties of graphene by creating defects is important from the point of view of thermal and stress management. Here we report Raman spectroscopic studies on pristine and plasma treated multilayer graphene to explore the remarkable structure and phonon properties with temperature and pressure. Temperature dependent studies illustrate monotonic softening of G and G′ bands in the temperature range 78 to 573 K. This process can be of fundamental importance in other promising and emerging nano and heterostructured materials. The pressure dependent Raman spectroscopic investigations on G-band of these samples were carried out up to 25 GPa using a diamond anvil cell. Comparatively weak and more compressible nature of the G band (E2g in-plane mode) as a function of applied pressure is found in plasma treated graphene. After pressure release, the samples recover to their original ordered structure. The present study is important for further understanding of the fine structure, properties and effect of defects in graphene, which can affect the atomic bonds, thermal expansion, specific heat, and thermal conductivity as well.

10agraphene10ahigh pressure10aPhonon10aPlasma treated graphene10aRaman spectroscopy1 aPawbake, Amit, S.1 aMishra, K., K.1 aMachuno, Luis, G. B.1 aGelamo, Rogerio, V.1 aRavindranathan, T., R.1 aRout, Chandra, Sekhar1 aLate, Dattatray, J. uhttps://library.ncl.res.in/content/temperature-and-pressure-dependent-raman-spectroscopy-plasma-treated-multilayer-graphene01727nas a2200217 4500008004100000022001400041245011800055210006900173260000900242300001200251490000700263520099200270653001501262653001001277653002301287653001101310653001901321100002401340700002401364856012101388 2019 eng d a2190-428600aTemperature-dependent Raman spectroscopy and sensor applications of PtSe2 nanosheets synthesized by wet chemistry0 aTemperaturedependent Raman spectroscopy and sensor applications  cFEB  a467-4740 v103 a

We report on a wet chemistry method used to grow PtSe2 nanosheets followed by thermal annealing. The SEM and TEM analysis confirms the formation of PtSe2 nanosheets. Furthermore, XRD, Raman, XPS and SAED patterns were used to analyze the crystal structure and to confirm the formation of the PtSe2 phase. The temperature-dependent Raman spectroscopy investigations were carried out on PtSe2 nanosheets deposited on Si substrates in the temperature range 100-506 K. The shifts in Raman active E-g and A(1g) modes as a function of temperature were monitored. The temperature coefficient for both modes was calculated and was found to match well with the reported 2D transition metal dichalcogenides. A PtSe2 nanosheet-based sensor device was tested for its applicability as a humidity sensor and photodetector. The humidity sensor based on PtSe2 nanosheets showed an excellent recovery time of approximate to 5 s, indicating the great potential of PtSe2 for future sensor devices.

10ananosheets10aPtSe210aRaman spectroscopy10aSensor10athermal effect1 aPawar, Mahendra, S.1 aLate, Dattatray, J. uhttps://library.ncl.res.in/content/temperature-dependent-raman-spectroscopy-and-sensor-applications-ptse2-nanosheets01943nas a2200241 4500008004100000022001400041245011600055210006900171260000800240300000800248490000800256520112400264653002101388653002101409653001301430653002901443653002301472653002001495100001901515700001801534700001801552856013101570 2021 eng d a0947-839600aSynthesis of graphene from activated carbon at liquid nitrogen temperature and its detailed structural analysis0 aSynthesis of graphene from activated carbon at liquid nitrogen t cMAY a3190 v1273 a

The present study deals with the synthesis of graphene using thermal quenching of pre-heated activated carbon (a-C) (1370 K for 3 h) at liquid nitrogen temperature and its detailed structural analysis using XRD, TEM, FTIR and Raman spectroscopy. The analysis of lattice parameters (L-a, L-c,L- and d) of constituent nanographitic domains using XRD shows restoration of graphene-like structure in the resultant product (a-CL). TEM image reveals porosity and partially crystallinity (from SAED) in a-C. While thin layers of graphene are observed in the TEM images of a-CL Deconvoluted Raman spectra have been used to investigate the evolution of crystalline behaviour of a-C with temperature in view of Ferrari and Robertson's three-stage model. The evolution of G peak and increase in I-D/I-G reveals restoration of crystallinity in a-CL. The development of the D peak indicates disordering of graphite but ordering of amorphous carbon. The reported method is technologically beneficial for graphene synthesis for large number of applications such as supercapacitors, H-2 storage, gas separation and purification.

10aactivated carbon10aAmorphous carbon10agraphene10aH-2 storage applications10aRaman spectroscopy10aSupercapacitors1 aSharma, Preeti1 aSharma, Geeta1 aPunia, Rajesh uhttps://library.ncl.res.in/content/synthesis-graphene-activated-carbon-liquid-nitrogen-temperature-and-its-detailed-structural01942nas a2200217 4500008004100000022001400041245016100055210006900216260000800285300001200293490000700305520114200312653001801454653002301472653003301495653001001528653001601538100002001554700001901574856013101593 2023 eng d a0377-048600aSystematic study of rare-earth ions size-dependent structural phase transition from monazite to zircon-type in rare earth chromates using Raman spectroscopy0 aSystematic study of rareearth ions sizedependent structural phas cJUL a793-8010 v543 a

Rare earth chromates (RCrO4) undergo monazite to zircon-type structural phase transition due to a decreased rare-earth ion size. They also exhibit an intermediate mixed phase. However, there is no systematic study on the influence of structural distortion on their phononic behavior, which is quite sensitive to subtle environmental variations. A change in the room temperature phononic spectrum was studied in the family of RCrO4 compounds, where R was varied from La to Yb using Raman modes. With an increase in the atomic number from Nd to Yb for zircon-type phases, the external translational and rotational modes were observed to shift towards lower and higher wavenumbers, respectively. At the same time, all internal vibrational modes shifted towards higher phonon energies. A comparison between Raman modes for monazite, intermediate, and zircon-type RCrO4 phases showed a gradual shift in the internal modes towards a higher wavenumber. The confirmation of the change in Raman modes with the decreasing radius was found by comparing the rare-earth elements in DyCrO4 and LaCrO4 with non-rare-earth elements in YCrO4.

10amonazite-type10aRaman spectroscopy10arare earth chromates (RCrO4)10aYCrO410azircon type1 aUghade, Supriya1 aPoddar, Pankaj uhttps://library.ncl.res.in/content/systematic-study-rare-earth-ions-size-dependent-structural-phase-transition-monazite-zircon