02022nas a2200241 4500008004100000022001400041245010300055210006900158260007400227300001200301490000700313520114200320653002001462653002101482653001901503653002601522653002301548100002201571700002001593700002001613700001901633856012801652 2005 eng d a1385-344900aCharacterization of barium titanate: BaTiO3 (BT) ceramics prepared from sol-gel derived BT powders0 aCharacterization of barium titanate BaTiO3 BT ceramics prepared  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcNOV a103-1080 v153 a

Sol-gel synthesis was attempted at room temperature by adding drop wise a clear solution (made by reacting BaCO3 with glacial acetic acid) to an equi-molar solution of titanium tetrabutoxide in isopropanol (IPA) and acetic acid. The gelation occurred within 30 minutes. The as-dried gel was calcined at 750 degrees C/6 h in air to obtain carbon free BaTiO3 powders. The resulting BT powders were further pressed into pellets and sintered at 1280 degrees C/4 h in air to get dense ceramics (density similar to 94%). XRD and SEM techniques were used for phase and microstructure analysis respectively. The room temperature relative permittivity (e) of 1280 increased to 7200 (at Curie temperature of 127 degrees C) at 1 kHz frequency. The dissipation factor (tan delta) similar to 1.6% was observed in these samples. Also, the ferroelectric properties such as spontaneous polarization (Ps similar to 13 mu C/cm(2)), coercive field (E-c similar to 4.0 kV/cm) and dielectric strength (similar to 34 kV/cm) are estimated for these samples. These performance parameters are compared with the available standard data from the literature.

10abarium titanate10aferroelectricity10aMicrostructure10arelative permittivity10asol-gel processing1 aDeshpande, S., B.1 aGodbole, P., D.1 aKhollam, Y., B.1 aPotdar, H., S. uhttp://library.ncl.res.in/content/characterization-barium-titanate-batio3-bt-ceramics-prepared-sol-gel-derived-bt-powders-001725nas a2200301 4500008004100000022001400041245009200055210006900147260007300216300001200289490000700301520070300308653003001011653003401041653001901075653003701094653001601131653000801147653000801155653000801163100002201171700002001193700002201213700002301235700002101258700001901279856012501298 2005 eng d a0167-577X00aSynthesis and characterization of microwave-hydrothermally derived Ba1-xSrxTiO3 powders0 aSynthesis and characterization of microwavehydrothermally derive aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a293-2960 v593 a

Submicron-sized, spherical, stoichiometric strontium substituted barium titanate: Ba0.75Sr0.25TiO3 (BST) powders are prepared by microwave-hydrothermal (MH) route under the MH conditions of 200 degreesC, 200 psi, and 30 min in strongly alkaline conditions (pH>12) using potassium titanyl oxalate (KTO) and nitrates of Ba and Sr as the starting precursors and KOH as the mineralizer. The characterization studies by XRD, XRF and SEM indicated that stoichiometric cubic BST powders (a(0)=3.992 A) were obtained by adjusting MH conditions mentioned earlier and keeping the (Ba+Sr)/Ti ratio in starting solution slightly in excess (similar to1.06). (C) 2004 Elsevier B.V. All rights reserved.

10abarium-strontium titanate10adissolution-recrystallization10aMicrostructure10amicrowave-hydrothermal synthesis10amineralizer10aSEM10aXRD10aXRF1 aDeshpande, S., B.1 aKhollam, Y., B.1 aBhoraskar, Y., B.1 aDate, Sadgopal, K.1 aSainkara, S., R.1 aPotdar, H., S. uhttp://library.ncl.res.in/content/synthesis-and-characterization-microwave-hydrothermally-derived-ba1-xsrxtio3-powders-002292nas a2200253 4500008004100000022001400041245009300055210006900148260013000217300001200347490000700359520135300366653001101719653004001730653001901770653001401789653001801803100002201821700001901843700001801862700002201880700002001902856011601922 2006 eng d a1226-086X00aDielectric properties of BaTiO3 ceramics prepared from powders with bimodal distribution0 aDielectric properties of BaTiO3 ceramics prepared from powders w aA-803 TWIN BLDG, 275-3, YANGJAE-DONG, SEOCHO-KU, SEOUL 137-130, SOUTH KOREAbKOREAN SOC INDUSTRIAL ENGINEERING CHEMISTRYcJUL a584-5880 v123 a

BaTiO3 (BT) powders having bimodal distribution were synthesized successfully through a simple classical solid-state reaction route using cheap BaCO3 and TiO2 as starting materials. These powders were further processed in the form of green pellets to obtain dense BT ceramics having densities of similar to 94 similar to 96 % after sintering in air at 1350 and 1400 degrees C/4 h in air. The room temperature dielectric constant (epsilon(RT)) of similar to 1500 at 1 KHz frequency was increased to : 10000 at a Curie temperature (T-C) similar to 126 degrees C, showing a very sharp transition from a polar tetragonal to a non-polar cubic structure. The dielectric loss factor (tan 6) was similar to 1.5 %. SEM studies revealed the presence of dense microstructures having a distribution of smaller grains (size: 2 similar to 3 gm) surrounded by larger grains (>= 35 mu m). The ferroelectric hysteresis loop measurements on these samples gave values of spontaneous polarization (P-s) of similar to 12.0 mu C/cm(2), a coercive field (E-C) of similar to 2 similar to 2.5 kV/cm, and a dielectric strength (E-b) of similar to 48.0 kV/cm. DC-resistivity as high as 1.5 x 10(9) Omega-cm was obtained in these samples. All these results are quite comparable with reported ferroelectric/dielectric data and are discussed elaborately in this paper.

10aBaTiO310adielectric-ferroelectric properties10aMicrostructure10aSintering10astoichiometry1 aDeshpande, S., B.1 aPotdar, H., S.1 aPatil, M., M.1 aDeshpande, V., V.1 aKhollam, Y., B. uhttp://library.ncl.res.in/content/dielectric-properties-batio3-ceramics-prepared-powders-bimodal-distribution-002168nas a2200253 4500008004100000022001400041245008600055210006900141260006900210300001200279490000700291520130700298653001901605653002101624653002301645653001201668100002201680700001901702700002001721700001801741700001701759700002201776856011601798 2006 eng d a0254-058400aRoom temperature synthesis of mesoporous aggregates of anatase TiO2 nanoparticles0 aRoom temperature synthesis of mesoporous aggregates of anatase T aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcJUN a207-2120 v973 a

The controlled hydrolysis reaction of titanium tetrabutoxide in presence of acetic acid in isopropanol, i.e. in non-aqueous media was adopted in the present work for the synthesis of nanocrystalline titania followed by aging at ambient conditions for longer duration. The powder XRD shows that the as-dried precursor (without any aging) is non-crystalline in nature. However, room temperature aging for longer duration > 120 days not only helped to develop crystallinity in TiO2 nanoparticles but also led to the formation of their self-assembly towards mesoporous aggregates creating sponge like TiO2 nano-structure having high surface area similar to 250m (2) g(-1)and narrow pore size distribution of 4-5 nm. TEM observations revealed the generation of spherical TiO2 nanoparticles (4-5 nm) assembled to form stable spongy scaffold having porous network structure with pore size 5-6 nm. Also, presence of a pronounced hysteresis loop in BET isotherm is indicative of a 3D-intersection network of the pores of size 4-5 nm. Further heat-treatment to the aged precursor at 400 degrees C/2 h in air modify pore network structure due to sintering of TiO2 particles as is observed in TEM studies and lowering thereby the surface area to 125 m(2) g(-1) (c) 2005 Elsevier B.V. All rights reserved.

10aMicrostructure10aporous materials10asol-gel processing10atitania1 aDeshpande, S., B.1 aPotdar, H., S.1 aKhollam, Y., B.1 aPatil, K., R.1 aPasricha, R.1 aJacob, Nalini, E. uhttp://library.ncl.res.in/content/room-temperature-synthesis-mesoporous-aggregates-anatase-tio2-nanoparticles-002204nas a2200205 4500008004100000022001400041245003400055210003400089260009900123300001200222490000700234520159000241653001901831653001301850653001401863100001701877700001601894700002101910856006701931 2006 eng d a0260-877400aStudies on shrikhand rheology0 aStudies on shrikhand rheology aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcMAY a169-1770 v743 a

Shrikhand, a popular Indian dessert made from yogurt, is manufactured on an industrial scale using several chemical engineering unit operations such as mixing, filtration and heat transfer. Understanding the rheology of shrikhand is not only relevant for designing large scale mixers but can also provide quantitative means for linking the microstructure of shrikhand to its perception of texture, consistency and taste. We show here that shrikhand exhibits a combination of several rheological properties such as weak gel-like viscoelasticity, an apparent yield stress, thixotropy and long structural recovery time scales. For instance, the elastic modulus is always higher than the loss modulus over the measurable frequency range and that both moduli show only weak frequency dependence that is a characteristic of gel-like consistency. Forward and reverse rate sweep tests show a distinct hysteresis loop, which is a signature of thixotropic character. In an attempt to trace the origins of these rheological properties in shrikhand we characterized its microstructure and showed that there exist two different microstructures: one composed of crystallites of milk fats having a length scale of similar to 50-100 mu m, and the other composed of aggregates of colloidal cascin micelles of similar to 0.5-10 mu m size. Our studies show that while the temperature sensitivity of the viscoelastic parameters is dominated by the semicrystalline milk fat microstructure, the shear sensitivity is largely dictated by the protein network. (c) 2005 Elsevier Ltd. All rights reserved.

10aMicrostructure10aRheology10ashrikhand1 aKulkarni, C.1 aBelsare, N.1 aLele, Ashish, K. uhttp://library.ncl.res.in/content/studies-shrikhand-rheology-001208nas a2200229 4500008004100000022001400041245004800055210004800103260006100151300001200212490000700224520051500231653002300746653002500769653001900794653001400813653002200827100001800849700001300867700001700880856008100897 2007 eng d a0250-470700aLow voltage varistor ceramics based on SnO20 aLow voltage varistor ceramics based on SnO2 a233 SPRING STREET, NEW YORK, NY 10013 USAbSPRINGERcDEC a583-5860 v303 a

The nonlinear current (I)-voltage (V) characteristics of tin dioxide doped with either Nb2O5 and CoO or Sb2O3 and CoO show promising values of nonlinear coefficient (alpha) values (similar to 11) with low breakdown voltages (E-B, similar to 40 V mm(-1)). The pentavalent antimony or niobium acts as donor and increases the electronic conductivity. The crucial parameter for obtaining low breakdown voltage is the grain size, which depends upon sintering duration and temperature of these oxide ceramics.

10aChemical synthesis10aelectronic materials10aMicrostructure10atin oxide10aX-ray diffraction1 aDhage, S., R.1 aRavi, V.1 aYang, O., B. uhttp://library.ncl.res.in/content/low-voltage-varistor-ceramics-based-sno2-002498nas a2200265 4500008004100000022001400041245016100055210006900216260006900285300001200354490000800366520146200374653003801836653003001874653001901904653002301923653003601946653002001982100001802002700002002020700002202040700002502062700002402087856012102111 2009 eng d a0254-058400aDoping-induced microstructural, textural and optical properties of In2Ti1-xVxO5+delta semiconductors and their role in the photocatalytic splitting of water0 aDopinginduced microstructural textural and optical properties of aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcOCT a399-4070 v1173 a

The physicochemical properties of V-doped indium titanates (In2Ti1-xVxO5-delta, 0.0 <= x <= 0.2) were investigated by using XPS, powder XRD, UV-vis, SEM and luminescence spectroscopy techniques. The Rietveld refinement of XRD data revealed that even though the V-containing samples were isostructural with In2TiO5 (orthorhombic space group Pnma), a systematic x-dependent variation was noticeable in the Ti-O bond lengths in [TiO6] octahedral units, cell parameters and in the value of delta. XPS results confirmed the coexistence of V5+ and V4+ states, leading thereby to an enhancement in oxygen non-stoichiometry in the doped samples. A loading-dependent progressive shift from 400 to 750 nm was also observed in the onset of the absorption edge, indicating a significant narrowing of the band gap. Furthermore, the samples with higher V-content were comprised of the grain clusters having larger size and an irregular shape. The UV-vis. photoluminescence and thermoluminescence studies indicate that the doping-induced lattice defects may give rise to certain closely spaced acceptor/donor energy levels in between the band gap of host matrix. The indium titanates are found to serve as stable photocatalysts for water splitting under visible light, where oxygen was the major reaction product. The role of microstructural and morphological properties in the photocatalytic activity is discussed. (C) 2009 Elsevier B.V. All rights reserved.

10aIn2Ti1-xVxO5+delta photocatalysts10aLuminescence spectroscopy10aMicrostructure10aOptical properties10aStructure-activity relationship10awater splitting1 aShah, Pallavi1 aBhange, Deu, S.1 aDeshpande, Aparna1 aKulkarni, Mukund, S.1 aGupta, Narendra, M. uhttp://library.ncl.res.in/content/doping-induced-microstructural-textural-and-optical-properties-in2ti1-xvxo5delta-002852nas a2200229 4500008004100000022001400041245014600055210006900201260006900270300001200339490000800351520198800359653001902347653001502366653001902381653001902400653001902419100002202438700002102460700001802481856012302499 2011 eng d a0254-058400aRole of lattice defects and crystallite morphology in the UV and visible-light-induced photo-catalytic properties of combustion-prepared TiO20 aRole of lattice defects and crystallite morphology in the UV and aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcAPR a546-5540 v1263 a

The physico-chemical, photo-physical and micro-structural properties responsible for the strikingly different photocatalytic behavior of combustion-prepared TiO2 (c.TiO2) and Degussa P25 (d.TiO2) samples are elucidated in this study. Electron microscopy and selected area electron diffraction micrographs revealed that the two samples exhibited different morphologies. The grains of c.TiO2 were spherical and comprised of 5-6 nm size primary particle. On the other hand, d.TiO2 consisted of large (0.5-3.0 mu m) size and irregular shape aggregates having primary particles of 15-40 nm cross-sectional diameter. The ESR study revealed that the presence of certain defect states in c.TiO2 helped in stabilization of O-. and Ti3+-OH type species during room-temperature UV-irradiation. No such paramagnetic species were however formed over d.TiO2 under similar conditions. C1s and Ti 2p XPS spectra provide evidence for the presence of some lattice vacancies in c.TiO2 and also for the bulk Ti4+ -> Ti3+ conversion during its UV-irradiation. Compared to d.TiO2, c.TiO2 displayed considerably higher activity for discoloration of methyl orange but very poor activity for splitting of water, both under UV and visible light radiations. This is attributed to enhanced surface adsorption of dye molecules over c.TiO2, because of its textural features and also the presence of photo-active ion-radicals. On the other hand, the poor activity of c.TiO2 for water splitting is related to certain defect-induced inter-band charge trapping states in the close vicinity of valence and conduction bands of c.TiO2, as revealed by thermoluminescence spectroscopy. Further, the dispersion of nanosize gold particles gave rise to augmented activity of both the catalysts, particularly for water splitting. This is explained by the promotional role of Au-0 or Au-0/TiO2 interfacial sites in the adsorption and charge-adsorbate interaction processes. (C) 2011 Elsevier B.V. All rights reserved.

10aBand-structure10aInterfaces10aMicrostructure10aNanostructures10aSemiconductors1 aDeshpande, Aparna1 aMadras, Giridhar1 aGupta, N., M. uhttp://library.ncl.res.in/content/role-lattice-defects-and-crystallite-morphology-uv-and-visible-light-induced-photo-001905nas a2200217 4500008004100000022001400041245011800055210006900173260010600242300001400348490000700362520106600369653001101435653002401446653001901470653001801489653002001507100002101527700001801548856012101566 2012 eng d a0360-319900aFactors affecting the production of H-2 by water splitting over a novel visible-light-driven photocatalyst GaFeO30 aFactors affecting the production of H2 by water splitting over a aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAR a4897-49070 v373 a

A d(10) photocatalyst, GaFeO3 having a band gap of similar to 2.7 eV, exhibits significant activity for the overall splitting of water under visible light (>395 nm) irradiation, in the absence of sacrificial reagent or a noble metal co-catalyst. The doping of an anion led to considerable enhancement in activity, the S-doped catalysts displaying better activity compared to the samples containing nitrogen. Even though the H-2/O-2 yields were affected by preparation-dependent grain morphology, no direct relationship was observed between the photoactivity of a sample and its specific surface area. The techniques of HRTEM, SEM, XPS, Laser Raman, UV-visible and photoluminescence spectroscopy have enabled to demonstrate that, besides the grain morphology, certain lattice imperfections and microstructure may also play a crucial role in water splitting activity of a photocatalyst. The factors responsible for catalyst deactivation are examined. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

10aGaFeO310ahydrogen production10aMicrostructure10aPhotocatalyst10awater splitting1 aDhanasekaran, P.1 aGupta, N., M. uhttp://library.ncl.res.in/content/factors-affecting-production-h-2-water-splitting-over-novel-visible-light-driven-002602nas a2200265 4500008004100000022001400041245010800055210006900163260007100232300001200303490000600315520165100321653001301972653002301985653001902008653001902027653001302046653002802059100002302087700002302110700002102133700002702154700002402181856013102205 2012 eng d a1543-838400aProbing influence of mesophasic transformation on performance of self-emulsifying system: effect of ion0 aProbing influence of mesophasic transformation on performance of a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB a318-3240 v93 a

Self-emulsifying systems are mixtures of oils and surfactants, ideally isotropic, sometimes including cosolvents, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastrointestinal tract. The process of self-emulsification has remained the center of attraction for most researchers. Controlled hydration of self-emulsifying systems shows formation of an intermediate gel phase which upon rupture forms an emulsion. Current work was undertaken to understand and explore the microstructural properties of intermediate gel phase which are believed to influence the performance (droplet size) of the final formulation. The effect of additives on microstructural properties of intermediate gel phase has also been investigated. Microstructural elucidation of hydrated samples of intermediate regimes was done by using techniques such as small angle X-ray scattering, differential scanning calorimetry and rheology. Samples from intermediate regimes showed formation of local lamellar structure which swelled with hydration. In the present work, the effect of addition of salt form of naproxen (sodium and potassium) and naproxen (base) on microstructural properties of intermediate regimes was investigated. Systems containing naproxen salts formed larger droplets whereas naproxen base formed smaller ones. Microstructural properties of intermediate lamellar structures were well correlated with performance of the final formulation. The current studies indicate that by controlling the properties of intermediate regimes optimized formulations with desired performance can be tailor-made.

10aemulsion10alamellar structure10aliquid crystal10aMicrostructure10aNaproxen10aself-emulsifying system1 aPatil, Sharvil, S.1 aVenugopal, Edakkal1 aBhat, Suresh, K.1 aMahadik, Kakasaheb, R.1 aParadkar, Anant, R. uhttp://library.ncl.res.in/content/probing-influence-mesophasic-transformation-performance-self-emulsifying-system-effect-ion-001677nas a2200229 4500008004100000022001400041245012700055210006900182260007300251300001100324490000800335520080900343653001901152653002401171653002101195653001901216653002001235653001801255100002801273700002501301856012101326 2013 eng d a0304-885300aInfluence of initial particle size on the magnetostriction of sintered cobalt ferrite derived from nanocrystalline powders0 aInfluence of initial particle size on the magnetostriction of si aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV a96-1020 v3463 a

The role of initial particle size on the magnetostriction coefficient of sintered cobalt ferrite derived from nanocrystalline powders is studied. Nanoparticles of cobalt ferrite with different sizes in the range 3-80 nm are synthesized by an autocombustion method using metal nitrates and glycine. It has been observed that the initial particle size of the starting powders has a strong influence on the magnetostrictive behavior of sintered cobalt ferrite. Highest magnetostrictive strain and strain derivative are obtained for sintered ferrite derived from nanoparticles of size < 5 nm. The results show that higher magnetostriction coefficient for sintered cobalt ferrite can be achieved by compacting nanocrystalline particles of very small size. (C) 2013 Elsevier B.V. All rights reserved.

10aCobalt ferrite10amagnetic properties10aMagnetostriction10aMicrostructure10aNanocrystalline10aParticle size1 aMohaideen, Kamal, Khaja1 aJoy, Pattayil, Alias uhttp://library.ncl.res.in/content/influence-initial-particle-size-magnetostriction-sintered-cobalt-ferrite-derived-002008nas a2200217 4500008004100000022001400041245014500055210006900200260009900269300001200368490000700380520113300387653001901520653002101539653001901560653002001579653001401599100002801613700002501641856012401666 2014 eng d a0955-221900aStudies on the effect of sintering conditions on the magnetostriction characteristics of cobalt ferrite derived from nanocrystalline powders0 aStudies on the effect of sintering conditions on the magnetostri aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcMAR a677-6860 v343 a

The effect of sintering conditions on the magnetostriction characteristics of sintered cobalt ferrite derived from nanocrystalline powders is studied. It is observed that the magnetostriction coefficient as well as the slope of the magnetostriction as a function of field depends on the microstructure of the sintered product. There is a direct correlation between the magnetostriction characteristics and density as well as porosity of the sintered products. Intragranular pores are found to be strongly influencing the magnetostriction characteristics. Similarly, correlation is found between the magnetostriction parameters and the Curie temperature, indicating the role of cation distribution which affects the magnetic anisotropy. Sintering the compacts made from nanocrystalline powders at 1450 degrees C for a very short duration is found to give high values of magnetostriction coefficient. However, higher values of magnetostriction at low magnetic fields are obtained for samples sintered at lower temperatures for longer duration and having relatively lower density. (C) 2013 Elsevier Ltd. All rights reserved.

10aCobalt ferrite10aMagnetostriction10aMicrostructure10aNanocrystalline10aSintering1 aMohaideen, Kamal, Khaja1 aJoy, Pattayil, Alias uhttp://library.ncl.res.in/content/studies-effect-sintering-conditions-magnetostriction-characteristics-cobalt-ferrite-002224nas a2200301 4500008004100000022001400041245013400055210006900189260006900258300001200327490000800339520114800347653003001495653001901525653001901544653002301563653003501586653003801621653001701659100001501676700001801691700001601709700001701725700001401742700002401756700002201780856012001802 2016 eng d a0254-058400aSynthesis and self-assembly of dumbbell shaped ZnO sub-micron structures using low temperature chemical bath deposition technique0 aSynthesis and selfassembly of dumbbell shaped ZnO submicron stru aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcFEB a152-1570 v1693 a

We report well dispersed horizontal growth of ZnO sub-micron structures using simplest technique ever known i.e. chemical bath deposition (CBD). A set of samples were prepared under two different cases A) dumbbell shaped ZnO grown in CBD bath and B) tubular ZnO structures evolved from dumbbell shaped structures by dissolution mechanism. Single phase wurtzite ZnO formation is confirmed using X-ray diffraction (XRD) technique in both cases. From the morphological investigations performed using scanning electron microscopy (SEM), sample prepared under case A indicate formation of hex bit tool (HBT) shaped ZnO crystals, which observed to self-organize to form dumbbell structures. Further these microstructures are then converted into tubular structures as a fragment of post CBD process. The possible mechanism responsible for the self-assembly of HBT units to form dumbbell structures is discussed. Observed free excitonic peak located at 370 nm in photoluminescence (PL) spectra recorded at 18 K indicate that the micro/nanostructures synthesized using CBD are of high optical quality. (C) 2015 Elsevier B.V. All rights reserved.

10aElectron microscopy (STEM10aMicrostructure10aNanostructures10aOptical properties10aPhotoluminescence spectroscopy10aRaman spectroscopy and scattering10aTEM and SEM)1 aBorade, P.1 aJoshi, K., U.1 aGokarna, A.1 aLerondel, G.1 aWalke, P.1 aLate, Dattatray, J.1 aJejurikar, S., M. uhttp://library.ncl.res.in/content/synthesis-and-self-assembly-dumbbell-shaped-zno-sub-micron-structures-using-low-002271nas a2200253 4500008004100000022001400041245006300055210006300118260000800181300001200189490000700201520153700208653002001745653001501765653000801780653001901788653001301807653001701820100002101837700002301858700002101881700002101902856009401923 2020 eng d a0035-451100aMicrostructure and yielding of capillary force induced gel0 aMicrostructure and yielding of capillary force induced gel cMAY a291-3060 v593 a

We have investigated the rheology and structure of a gel formed from a mixture of non-Brownian particles and two immiscible liquids. The suspension of particles in a liquid undergoes gelation upon the addition of a small content of second, wetting liquid which forms liquid bridges between particles leading to a sample spanning network. The rheology of this gel primarily exhibits a yield stress at low shear rates followed by a linear variation of shear stress at high shear rates. The apparent yield stress extracted from the flow curves increases rapidly with volume fraction of the second liquid before saturation, while it exhibits a monotonic increase with increasing particle concentration. Rescaling of the yield stress curves using suitable shift factors results in an empirical expression for the yield stress showing squared dependence on liquid fraction and a rapid increase with particle fraction above a certain value, both combined in a highly non-linear manner. The microstructural variations with changing secondary liquid content and particle fractions are captured using three-dimensional X-ray tomography technique. The microstructure is observed to show increased local compactness with increased liquid content and increased spatial homogeneity with increased particle fractions. The images from X-ray tomography are analysed to obtain the distributions of particle-particle bonds (coordination number) in the system which serve to explain the observed yield stress behaviour in a qualitative manner.

10aCapillary force10aFlow curve10agel10aMicrostructure10aRheology10aYield stress1 aHuprikar, Sameer1 aUsgaonkar, Saurabh1 aLele, Ashish, K.1 aOrpe, Ashish, V. uhttp://library.ncl.res.in/content/microstructure-and-yielding-capillary-force-induced-gel01848nas a2200241 4500008004100000022001400041245010500055210006900160260000900229300001100238490000800249520104200257653001301299653001801312653001701330653001901347653001401366653001801380100002301398700002301421700003701444856012501481 2021 eng d a0167-577X00aRole of Nd3+ concentration on the microstructure and scintillation behaviour of langbeinite sulphate0 aRole of Nd3 concentration on the microstructure and scintillatio cFEB  a1289970 v2843 a

Langebeinite (K2Ca2(SO4)(3)) ceramics doped with increasing concentrations of Nd3+ ions (0.01-0.04 mol%) was prepared by wet chemical precipitation and calcination at 800 degrees C. Thermal studies revealed high temperature stability of the phosphors. UV-VIS-NIR spectroscopic analysis of phosphors reveal strong absorption peaks representing f -> f transitions. Direct bandgap derived from Kubelka-Munk plot was found to be similar to 5.66 eV. FTIR studies reveal tetrahedral symmetry of the SO42 ions. SEM micrographs reveal the formation of phosphors with wide particle size distribution and elemental composition was analysed using EDX studies. Scintillation studies representing a single high intensity peak around 784 nm is ascribed to I-4(9/2) -> F-4(5/2) + H-2(9/2) transition. Langbeinite phosphor with 0.02 mol% of Nd3+ exhibited maximum emission intensity indicating optimal concentration for scintillation studies favouring the development of NIR emitting phosphors. (c) 2020 Elsevier B.V. All rights reserved.

10aCeramics10aLangebeinites10aLuminescence10aMicrostructure10aNeodymium10aScintillation1 aPoornima, Velswamy1 aMohan, Subramaniam1 aUma, Tiruchirappalli, Sivagnanam uhttp://library.ncl.res.in/content/role-nd3-concentration-microstructure-and-scintillation-behaviour-langbeinite-sulphate01686nas a2200253 4500008004100000022001400041245014600055210006900201260000800270300001200278490000700290520080300297653001901100653001501119653002401134653001601158653002501174653002801199100001801227700002701245700001601272700002601288856011801314 2023 eng d a2159-685900aUnleashing methylammonium-guanidinium lead iodide hybrid perovskite spherulitic microstructures: a structural and morphological investigation0 aUnleashing methylammoniumguanidinium lead iodide hybrid perovski cJUN a406-4150 v133 a

Perovskites can offer an attractive replacement option for existing commercial solar technologies. Herein microstructure plays an important role in improving the efficiency and stability of solar cells. Previously unidentified spherulitic microstructures of self-assembled polycrystalline perovskites are explored in this report. For this an intermediate phase of a promising guanidinium (GUAI)-rich perovskite has been investigated for its structural and morphological properties. This study infuses new insight into the evolution of perovskite microstructure from heterogeneity to homogeneity, as a result unravels the structure of perovskite embryonic spherulites, lamellar arrangements, transcrystalline nature, novel spherulites bridging, hole nucleation, impingement, and defects.

10aMicrostructure10aMorphology10aNucleation & growth10aPerovskites10aPhase transformation10aX-ray diffraction (XRD)1 aMukul, Monika1 aKaliaperumal, Selvaraj1 aRani, Mamta1 aTripathi, Surya, Kant uhttp://library.ncl.res.in/content/unleashing-methylammonium-guanidinium-lead-iodide-hybrid-perovskite-spherulitic