02023nas a2200241   4500008004100000022001400041245010300055210006900158260007400227300001200301490000700313520114200320653002001462653002101482653001901503653002601522653002301548100002201571700002001593700002001613700001901633856012901652       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<p>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.</p>10abarium titanate10aferroelectricity10aMicrostructure10arelative permittivity10asol-gel processing1 aDeshpande, S., B.1 aGodbole, P., D.1 aKhollam, Y., B.1 aPotdar, H., S.  uhttps://library.ncl.res.in/content/characterization-barium-titanate-batio3-bt-ceramics-prepared-sol-gel-derived-bt-powders-002286nas a2200217   4500008004100000020001800041245009800059210006900157260009600226300001200322520144500334100002001779700001801799700001401817700001901831700002201850700002501872700002301897700001901920856012901939       2005                        eng d  a1-57498-218-400aMagnetic properties of nanosized ferrite powders synthesized by microwave-hydrothermal method0 aMagnetic properties of nanosized ferrite powders synthesized by   aSan Francisco, CAbAmer Ceramic Soc, 735 Ceramic Place, Westerville, OH 43081-8720 USAcAUG  a143-1483 a<p>Nanosized powders of Fe3O4 and MgFe2O4 are synthesized by microwave-hydrothermal (MH) method. The ferrite powders thus obtained are characterized by powder X-ray diffraction, Mossbauer spectroscopy, scanning and transmission electron microscopies, vibrating sample magnetometer and AC magnetic susceptibility studies. Stoichiometric, nanosized (similar to 34 nm) Fe3O4 particles, having cubic symmetry with a(0) approximate to 8.39 angstrom, are obtained when molar ratio of Fe/NaOH used for the synthesis is 0.133. On the other hand, non-stoichiometric Fe3O4 is obtained when Fe/NaOH molar ratio is increased to 0.4. Though the powder XRD patterns of both stoichiometric and non-stoichiometric Fe3O4 are identical, Mossbauer spectroscopic studies showed different features in terms of asymmetry, intensity, isomer shift, etc. Saturation magnetization, M-s = 70 emu/g and coercivity, H-c = 178 Oe, at room temperature, are obtained for stoichiometric Fe3O4 powders. In the case of MgFe2O4, spherical, nanosized (similar to 3 nm) powders with cubic symmetry (a(0) approximate to 8.30 angstrom) and having very narrow size distribution are obtained under the MH conditions. The temperature and field dependent magnetic measurements on MgFe2O4 powders confirmed the existence of superparamagnetic state in this material with a superparamagnetic blocking temperature of 38 K below which typical magnetic hysteresis behaviour is observed.</p>1 aKhollam, Y., B.1 aDhage, S., R.1 aVerma, S.1 aPotdar, H., S.1 aDeshpande, S., B.1 aJoy, Pattayil, Alias1 aDate, Sadgopal, K.1 aSoohoo, R., F.  uhttps://library.ncl.res.in/content/magnetic-properties-nanosized-ferrite-powders-synthesized-microwave-hydrothermal-method-002118nas a2200253   4500008004100000022001400041245010600055210006900161260007900230300001000309490000700319520118900326653003001515653003701545653001701582653000801599100002001607700002201627700001901649700002201668700002001690700002301710856013101733       2005                        eng d  a1044-580300aSimple oxalate precursor route for the preparation of barium-strontium titanate: Ba1-xSrxTiO3 powders0 aSimple oxalate precursor route for the preparation of bariumstro  a360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USAbELSEVIER SCIENCE INCcJAN  a63-740 v543 a<p>A simple one-step cation-exchange reaction between the stoichiometric solutions of ammonium titanyl oxalate (ATO) and barium hydroxide+strontium nitrate at room temperature (RT) is investigated successfully for the quantitative precipitation of barium-strontium titanyl oxalate (BSTO): Ba1-xSrxTiO(C2O4)(2).4H(2)O (x=0.25) precursor powders with nearly theoretical yield (greater than or equal to99%). The pyrolysis of BSTO at 730degreesC/4 h in air produced barium-strontium titanate (Ba1-xSrxTiO3; BST) powders. The characterization studies on BSTO and BST powders by using various physico-chemical techniques: micro- and chemical analysis, differential thermal analysis (DTA)/thermo-gavimetric analysis (TGA), XRD, FTIR, X-ray fluorescence (XRF) and scanning electron microscopy (SEM) revealed that the powders formed are cubic, highly pure, stoichiometric and sub-micron-sized with nearly uniform size and shape distribution. The ceramic compacts obtained by sintering the BST pellets at 1300degreesC/4 It showed density similar to95%, dielectric constant epsilon(Tc)similar to9500, tan delta-0.15% and T(C)similar to32 degreesC. (C) 2004 Elsevier Inc. All rights reserved.</p>10abarium-strontium titanate10abarium-strontium titanyl oxalate10apermittivity10aXRF1 aKhollam, Y., B.1 aDeshpande, S., B.1 aPotdar, H., S.1 aBhoraskar, S., V.1 aSainkar, S., R.1 aDate, Sadgopal, K.  uhttps://library.ncl.res.in/content/simple-oxalate-precursor-route-preparation-barium-strontium-titanate-ba1-xsrxtio3-powders-001726nas a2200301   4500008004100000022001400041245009200055210006900147260007300216300001200289490000700301520070300308653003001011653003401041653001901075653003701094653001601131653000801147653000801155653000801163100002201171700002001193700002201213700002301235700002101258700001901279856012601298       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<p>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&gt;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.</p>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.  uhttps://library.ncl.res.in/content/synthesis-and-characterization-microwave-hydrothermally-derived-ba1-xsrxtio3-powders-002293nas a2200253   4500008004100000022001400041245009300055210006900148260013000217300001200347490000700359520135300366653001101719653004001730653001901770653001401789653001801803100002201821700001901843700001801862700002201880700002001902856011701922       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<p>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 (&gt;= 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.</p>10aBaTiO310adielectric-ferroelectric properties10aMicrostructure10aSintering10astoichiometry1 aDeshpande, S., B.1 aPotdar, H., S.1 aPatil, M., M.1 aDeshpande, V., V.1 aKhollam, Y., B.  uhttps://library.ncl.res.in/content/dielectric-properties-batio3-ceramics-prepared-powders-bimodal-distribution-001611nas a2200289   4500008004100000022001400041245012700055210006900182260010600251300001400357490000700371520056300378653002200941653003200963653001400995653002701009653000801036100002201044700002001066700002401086700001701110700001901127700001801146700001601164700002201180856011901202       2006                        eng d  a1359-646200aPreparation of gamma-Fe2O3 nanoparticles using DC thermal arc-plasma route, their characterization and magnetic properties0 aPreparation of gammaFe2O3 nanoparticles using DC thermal arcplas  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcAPR  a1235-12400 v543 a<p>gamma-Fe2O3 particles were prepared, for the first time, using a direct current thermal arc-plasma route. The powder was characterized using X-ray diffraction, Mossbauer spectroscopy, X-ray photoelectron spectroscopy, chemical analysis, vibrating sample magnetometry C and transmission electron microscopy. The high purity, stoichiometry and spherical morphology of the gamma-Fe2O3 particles (saturation magnetization = 79 emu g(-1) and coercivity = 348 Oe) were confirmed. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</p>10achemical analysis10aDC thermal arc-plasma route10amaghemite10aMossbauer spectroscopy10aXPS1 aBanerjee, Indrani1 aKhollam, Y., B.1 aBalasubramanian, C.1 aPasricha, R.1 aBakare, P., P.1 aPatil, K., R.1 aDas, A., K.1 aBhoraskar, S., V.  uhttps://library.ncl.res.in/content/preparation-gamma-fe2o3-nanoparticles-using-dc-thermal-arc-plasma-route-their-002169nas a2200253   4500008004100000022001400041245008600055210006900141260006900210300001200279490000700291520130700298653001901605653002101624653002301645653001201668100002201680700001901702700002001721700001801741700001701759700002201776856011701798       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<p>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 &gt; 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.</p>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.  uhttps://library.ncl.res.in/content/room-temperature-synthesis-mesoporous-aggregates-anatase-tio2-nanoparticles-002227nas a2200241   4500008004100000022001400041245005500055210005200110260006900162300001200231490000700243520144600250653003001696653003701726653001801763653002101781653001501802100002001817700001901837700002201856700002001878856008701898       2006                        eng d  a0254-058400aSynthesis of star shaped Ba1-xSrTiO3 (BST) powders0 aSynthesis of star shaped Ba1xSrTiO3 BST powders  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcJUN  a295-3000 v973 a<p>Uniform star shaped strontium substituted barium titanyl oxalate Ba1-xSrxTiO(C2O4)(2) (BSTO)/strontium substituted barium titanate, Ba1-xSrxTiO3 (BST) powders were prepared via a simple chemical co-precipitation route with x = 0.15, 0.20, and 0.25. The process involved an addition of 0.1 M solution of titanium tetrabutoxide (BTM) in isopropanol (IPA) to 0.1 M oxalic acid in IPA containing 0.2 M of H2O to produce titanyl oxalate precipitate which was further reacted with 0.1 M solution of ammonium oxalate to obtain 0.1 M clear homogeneous solution of ammonium titanyl oxalate (ATO) with pH 4.25 containing titanium in the form of soluble anionic oxalate species [TiO(C2O4)(2)(2-)]. Stoichiometric quantities of barium hydroxide and strontium nitrate were dissolved in distilled water and its pH was adjusted nearly equal to that of ATO (similar to 4.15) by drop wise addition of dilute HNO3 solution 1:10 (v/v). The addition of this mixed cation precursor solution to ATO solution resulted in precipitation of strontium substituted barium titanyl oxalate (BSTO) having star shaped morphology. The calcination of BSTO precursors at 730 degrees C for 4 h in air produced cubic BST powders (a(o) similar to 4.001, 3.996 and 3.991 angstrom for x = 0. 15, 0.20, 0.25, respectively) having star shaped morphology. SEM, XRD and IFTIR techniques were used to characterize the BSTO/BST powders. (c) 2005 Elsevier B.V. All rights reserved.</p>10abarium-strontium titanate10abarium-strontium titanyl oxalate10acapping agent10aCo-precipitation10aMorphology1 aKhollam, Y., B.1 aPotdar, H., S.1 aDeshpande, S., B.1 aGaikwad, A., B.  uhttps://library.ncl.res.in/content/synthesis-star-shaped-ba1-xsrtio3-bst-powders-101752nas a2200229   4500008004100000022001400041245012000055210006900175260008900244300001000333490000700343520092300350653001401273653001801287653000801305653000801313100002001321700002201341700001501363700001901378856012501397       2008                        eng d  a0971-458800aSynthesis of bismuth titanate (Bi4Ti3O12)powders via calcination of microwave-hydrothermally (MH) derived precursor0 aSynthesis of bismuth titanate Bi4Ti3O12powders via calcination o  aDR K S KRISHNAN MARG, NEW DELHI 110 012, INDIAbNATL INST SCIENCE COMMUNICATIONcFEB  a51-540 v153 a<p>Micrometer sized platelet-like particles of bismuth titanate (Bi4Ti3O12) ire prepared successfully by the calcination of a mixed-precursor in air. The mixed precursor is precipitated Under microwave-hydrothermal (MH) treatment via dissolution-recrystallization kinetics. The mixed precursor is precipitated in-situ by giving MH treatment (at 200 degrees C, 200 psi, and 30 min hold time) to the hydrolysed slurry containing Bi and Ti cations. The slurry was prepared by adding 20% aqueous KOH precipitant solution to a well-mixed stoichiometric nitrate solution containing Bi and Ti cations. XRD results revealed that the as-dried precursor consisted of a homogenous mixture of non-crystalline particles of Bi2O3 and TiO2. The calcination of the as-dried precursor at 700 degrees C/2 h in air resulted ill the formation of micron sized platelet like single-phase Bi4Ti3O12 powders having orthorhombic structure.</p>10aBi4Ti3O1210aMH processing10aSEM10aXRD1 aKhollam, Y., B.1 aDeshpande, S., B.1 aSamuel, V.1 aPotdar, H., S.  uhttps://library.ncl.res.in/content/synthesis-bismuth-titanate-bi4ti3o12powders-calcination-microwave-hydrothermally-mh-001448nas a2200193   4500008004100000022001400041245010600055210006900161260009900230300001400329490000700343520067500350100002201025700002001047700002201067700001601089700002201105856012701127       2010                        eng d  a0734-210100aStudy of the effect of plasma-striking atmosphere on Fe-oxidation in thermal dc arc-plasma processing0 aStudy of the effect of plasmastriking atmosphere on Feoxidation   aSTE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USAbA V S AMER INST PHYSICScNOV  a1399-14030 v283 a<p>The effect of plasma-striking atmosphere: air and air+Ar-gas on the crystallization of Fe-oxide phases was studied using dc thermal arc-plasma processing route. The powders were characterized by x-ray diffraction, vibrating sample magnetometry, transmission electron microscopy, and Mossbauer spectroscopy techniques. At room temperature and O(2) rich atmosphere, arc-evaporated Fe(2+) ions oxidize into either gamma-Fe(2)O(3) or Fe(3)O(4) depending upon the combining ratio of Fe with molecular O(2). Fe/O ratio could be adjusted using proper flow rate of Ar gas to crystallize the pure gamma-Fe(2)O(3). (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3504597]</p>1 aBanerjee, Indrani1 aKhollam, Y., B.1 aMahapatra, S., K.1 aDas, A., K.1 aBhoraskar, S., V.  uhttps://library.ncl.res.in/content/study-effect-plasma-striking-atmosphere-fe-oxidation-thermal-dc-arc-plasma-processing-002266nas a2200169   4500008004100000022001400041245006400055210005800119260022900177300001000406490000800416520151700424100002201941700002001963700001901983856009402002       2011                        eng d  a0015-019300aMicrowave-hydrothermal (MH) synthesis of Ba1-xSrxTiO3 (BST)0 aMicrowavehydrothermal MH synthesis of Ba1xSrxTiO3 BST  a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbDept Sci & Technol; Defense R& D Org; Council Sci & Ind Res; Mat Res Soc India; Indian Inst Sci; IEEE UFFC; Taylor & Francis Sci Publ; Int Journal FERROELECTcMAR  a39-430 v3273 a<p>The barium-strontium titanate (BST) powders are used in fabrication of various microelectronic devices (because of their field- &amp; composition dependent dielectric properties), integrated capacitors &amp; as thin dielectric layer in DRAM (dynamic random access memories). The utility of MH synthesis route in deriving the BST powders was explored in the present studies under strongly alkaline conditions (pH &gt; 12). Potassium titanyl oxalate (KTO) and nitrates of Ba &amp; Sr were used as the starting precursors and KOH as a mineralizer. The typical BST composition, namely, BST with Sr = 0.25 was chosen for the experimentation. All the MH experiments were carried out in the MARS-5 microwave accelerated digestion system (CEM Corpn., USA). The stoichiometric BST powders were obtained under the MH conditions of 200 degrees C, 200 psi, and 30 min when the Ba/Sr ratio (greater than or similar to 3.25) was kept slightly in excess. The acetic acid treated and water washed MH derived powders showed formation of exclusively cubic BST phase (a(0) = 3.992 A degrees) as confirmed by XRD. These powders were further processed in the form of disks and sintered at high temperature (1350 degrees C/4 h) in air to obtain dense (rho &gt;= 92%) ceramic bodies. Electrical measurements on the lapped and electroded samples (sintered at 1350 degrees C/4h) revealed epsilon(T-c) = 6800, tan delta = 0.1% and T-c = 32 degrees C. These properties are comparable to the reported standard data in the literature.</p>1 aDeshpande, S., B.1 aKhollam, Y., B.1 aPotdar, H., S.  uhttps://library.ncl.res.in/content/microwave-hydrothermal-mh-synthesis-ba1-xsrxtio3-bst-002128nas a2200277   4500008004100000022001400041245007700055210006900132260008800201300001200289490000700301520119600308653001701504653001401521653002301535653002501558653002801583100001701611700002001628700002401648700001801672700001701690700001601707700001901723856010801742       2015                        eng d  a0217-984900aBiosynthesis of silver nanoparticles by using ganoderma-mushroom extract0 aBiosynthesis of silver nanoparticles by using ganodermamushroom   a5 TOH TUCK LINK, SINGAPORE 596224, SINGAPOREbWORLD SCIENTIFIC PUBL CO PTE LTDcMAR  a15400470 v293 a<p>Present study reports the biochemical synthesis of silver nanoparticles (Ag-NPs) from aqueous medium by using the extract of medicinal mushroom Ganoderma, as a reducing and stabilizing agents. The Ag-NPs are prepared at room temperature by the reduction of Ag+ to Ag in aqueous solution of AgNO3. The resultant particles are characterized by using UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) measurement techniques. The formation of Ag-NPs is confirmed by recording the UV-visible absorption spectra for surface plasmon resonance (SPR) where peak around 427 nm. The prominent changes observed in FTIR spectra supported the reduction of Ag+ to Ag. The morphological features of Ag-NPs are evaluated from HRTEM. The spherical Ag-NPs are observed in transmission electron microscopy (TEM) studies. The particle size distribution is found to be nearly uniform with average particle size of 2 nm. The Ag-NPs aged for 15, 30, 60 and 120 days showed no profound effect on the position of SPR peak in UV-visible studies, indicating the protecting/capping ability of medicinal mushroom Ganoderma in the synthesis of AgNPs.</p>10aBiosynthesis10aGanoderma10amedicinal mushroom10asilver nanoparticles10aUV-visible spectroscopy1 aEkar, S., U.1 aKhollam, Y., B.1 aKoinkar, Pankaj, M.1 aMirji, S., A.1 aMane, R., S.1 aNaushad, M.1 aJadhav, S., S.  uhttps://library.ncl.res.in/content/biosynthesis-silver-nanoparticles-using-ganoderma-mushroom-extract-1