01277nas a2200169   4500008004100000022001400041245007700055210006900132260007400201300001200275490000700287520065900294100002000953700001800973700001300991856010301004       2005                        eng d  a0957-452200aCo-precipitation method for the preparation of ferroelectric CaBi4Ti4O150 aCoprecipitation method for the preparation of ferroelectric CaBi  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcAPR  a229-2310 v163 a<p>A simple co-precipitation technique has been successfully applied for the preparation of pure single phase CaBi4Ti4O15 (CBT) powders. Ammonium oxalate and ammonium hydroxide were used to precipitate Ca2+, Bi3+ and Ti4+ cations simultaneously. No pyrochlore phase was found while heating powder at 600&amp;DEG; C and pure CBT phase was found to be formed by X-ray diffraction. Particle size and morphology was studied by transmission electron microscopy (TEM). The room temperature dielectric constant at 1 kHz is 400. The ferroelectric hysteresis loop parameters of these samples were also studied. (C) 2005 Springer Science + Business Media, Inc.</p>1 aGaikwad, S., P.1 aDhage, S., R.1 aRavi, V.  uhttps://library.ncl.res.in/content/co-precipitation-method-preparation-ferroelectric-cabi4ti4o15-001502nas a2200253   4500008004100000022001400041245010100055210006900156260007400225300001000299490000700309520062700316653001300943653002300956653002500979653002101004653001101025100002001036700001801056700001901074700001501093700001301108856012701121       2005                        eng d  a1385-344900aCo-precipitation method for the preparation of nanocrystalline ferroelectric SrBi2Nb2O9 ceramics0 aCoprecipitation method for the preparation of nanocrystalline fe  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcJAN  a83-870 v143 a<p>A simple co-precipitation technique had been successfully applied for the preparation of pure ultrafine single phase SrBi2Nb2O9. Ammonium hydroxide and ammonium oxalate were used to precipitate Sr2+, Bi3+ and Nb5+ cations simultaneously. No pyrochlore phase was found while heating powder at 850 C and pure SrBi2Nb2O9 (SBN) phase was formed as revealed by the X-ray diffraction (XRD) studies. Particle size and morphology was studied by transmission electron microscopy (TEM). The room temperature dielectric constant at 1 kHz is 100. The ferroelectric hysteresis loop parameters of these samples were also studied.</p>10aCeramics10aChemical synthesis10aelectronic materials10aferroelectricity10aOxides1 aGaikwad, S., P.1 aDhage, S., R.1 aPotdar, H., S.1 aSamuel, V.1 aRavi, V.  uhttps://library.ncl.res.in/content/co-precipitation-method-preparation-nanocrystalline-ferroelectric-srbi2nb2o9-ceramics-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-001545nas a2200229   4500008004100000022001400041245005700055210005700112260007300169300001400242490000700256520082500263653001301088653002301101653002401124653002101148653001101169100001801180700001701198700001301215856008701228       2005                        eng d  a0167-577X00aPreparation of ferroelectric BaNb2O6 the urea method0 aPreparation of ferroelectric BaNb2O6 the urea method  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a1929-19310 v593 a<p>A precipitate was formed when an aqueous solution of BaCl2, NbF5 and urea in required ratio (the ratio of total metal cations to the urea is five) is heated on a water bath at 100 degrees C. This precipitate on decomposition at 600 degrees C yielded the nanocrystallites of BaNb2O6 (BN), 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 microscope (TEM) investigations revealed that the average particle size is 85 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found to be 900. The ferroelectric hysteresis loop parameters of these samples were also studied. (c) 2005 Elsevier B.V. All rights reserved.</p>10aCeramics10aChemical synthesis10aelectronic material10aferroelectricity10aOxides1 aDhage, S., R.1 aPasricha, R.1 aRavi, V.  uhttps://library.ncl.res.in/content/preparation-ferroelectric-banb2o6-urea-method-001449nas a2200241   4500008004100000022001400041245006200055210006200117260007300179300001400252490000700266520067700273653001300950653002300963653002400986653001101010653002201021100001801043700002201061700001801083700001301101856009301114       2005                        eng d  a0167-577X00aSynthesis of bismuth oxide nanoparticles at 100 degrees C0 aSynthesis of bismuth oxide nanoparticles at 100 degrees C  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a2523-25250 v593 a<p>A simple gel to crystal conversion route has been followed for the preparation of ultrafine Bi2O3 particles at 80-100 degrees C under refluxing conditions. Freshly prepared bismuth hydroxide gel is allowed to crystallize under refluxing and stirring conditions for 6-12 h. Formation of nanocrystallites of Bi2O3 is confirmed by X-ray diffraction (XRD) study. The thermal decomposition of bismuth hydroxide yields Bi2O3 only at 400 degrees C. This shows the advantage of the present method. Transmission electron microscope (TEM) investigations revealed that the average particle size is 50 nm for these oven-dried powders. (c) 2005 Elsevier B.V All rights reserved.</p>10aCeramics10aChemical synthesis10aElectron microscopy10aOxides10aX-ray diffraction1 aPatil, M., M.1 aDeshpande, V., V.1 aDhage, S., R.1 aRavi, V.  uhttps://library.ncl.res.in/content/synthesis-bismuth-oxide-nanoparticles-100-degrees-c-001468nas a2200229   4500008004100000022001400041245005300055210005300108260007300161300001200234490000700246520074800253653001301001653002301014653002601037653002101063653002201084100002101106700001801127700001301145856008001158       2005                        eng d  a0167-577X00aSynthesis of bismuth titanate by the urea method0 aSynthesis of bismuth titanate by the urea method  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a514-5160 v593 a<p>A simple urea precipitation route was adopted for the preparation of bismuth titanate (Bi4Ti3O12) powders. Stoichiometric quantities of BiCl3 and TiOCl2 were mixed with the required amount of urea (the ratio of total metal cations to urea is five), and the mixture was heated on a water bath. This leads to the formation of precipitate, which was decomposed at 973 K. The formation of bismuth titanate was observed on calcining powders at 973 K by X-ray diffraction studies. The average particle size is found to be 100 nm by microscopy. The room temperature dielectric constant is found to be 150 at 1 kHz. The hysteresis loop parameters were also obtained by home-built Sawer-Tower circuit. (C) 2004 Elsevier B.V. All rights reserved.</p>10aCeramics10aChemical synthesis10adielectric properties10aferroelectricity10aX-ray diffraction1 aAnilkumar, Mettu1 aDhage, S., R.1 aRavi, V.  uhttps://library.ncl.res.in/content/synthesis-bismuth-titanate-urea-method-001328nas a2200241   4500008004100000022001400041245004900055210004700104260009900151300001200250490000700262520058100269653000900850653002500859653002400884653001200908653001800920100001800938700002000956700001900976700001300995856007801008       2005                        eng d  a0272-884200aSynthesis of Ce0.75Zr0.25O2 at 100 degrees C0 aSynthesis of Ce075Zr025O2 at 100 degrees C  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcJAN  a211-2130 v313 a<p>A simple gel to crystal conversion route has been used for the preparation of Ce0.75Zr0.25O2 phase at 80-100degreesC under refluxing conditions. Freshly prepared metal hydroxides gel from cerium and zirconium salt solution is allowed to crystallize under refluxing and stirring conditions for 4-10 h. Formation of nano crystallites of Ce0.75Zr0.25O2 is confirmed by X-ray diffraction (XRD). Transmission electron microscopy (TEM) investigations revealed the average particle size of these powders to be 5 nm. (C) 2004 Elsevier Ltd and Techna S.r.l. All rights reserved.</p>10aCeO210achemical preparation10aElectron microscopy10apowders10aX-ray methods1 aDhage, S., R.1 aGaikwad, S., R.1 aMuthukumar, P.1 aRavi, V.  uhttps://library.ncl.res.in/content/synthesis-ce075zr025o2-100-degrees-c-001228nas a2200229   4500008004100000022001400041245005600055210005600111260007300167300001200240490000700252520051400259653001300773653002300786653002400809653001100833653002200844100001800866700001700884700001300901856008400914       2005                        eng d  a0167-577X00aSynthesis of fine particles of ZnO at 100 degrees C0 aSynthesis of fine particles of ZnO at 100 degrees C  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a779-7810 v593 a<p>A simple gel to crystal conversion route has been followed for the preparation of fine ZnO at 80-100 degreesC under refluxing conditions. Freshly prepared zinc hydroxide gel is allowed to crystallize under refluxing and stirring conditions for 4-6 It. Formation of fine crystallites of ZnO is confirmed by X-ray diffraction (XRD) study. Transmission electron microscope (TEM) investigations revealed that the average particle size is 100 nm for these powders. (C) 2004 Elsevier B.V All rights reserved.</p>10aCeramics10aChemical synthesis10aElectron microscopy10aOxides10aX-ray diffraction1 aDhage, S., R.1 aPasricha, R.1 aRavi, V.  uhttps://library.ncl.res.in/content/synthesis-fine-particles-zno-100-degrees-c-001488nas a2200217   4500008004100000022001400041245004800055210004600103260007300149300001400222490000700236520083300243653001301076653002401089653002101113653001101134100001801145700001701163700001301180856007701193       2005                        eng d  a0167-577X00aSynthesis of Sr0.5Ba0.5Nb2O6 by urea method0 aSynthesis of Sr05Ba05Nb2O6 by urea method  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a1053-10550 v593 a<p>A precipitate was formed when an aqueous solution of SrCl2, BaCl2, NbF5 and urea in stoichiometric ratio (total metal cations to urea ratio is 5) is heated on a water bath.. This precipitate on decomposition at 750 degreesC yielded the nanocrystallites of ternary oxide, Sr0.5Ba0.5Nb2O6 (SBN) as confirmed by X-ray diffraction study (XRD). This is much lower temperature as compared to that prepared by traditional solid state method (1000 degreesC as reported for the formation of SBN ceramics. 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 1050. The ferroelectric hysteresis loop parameters of these samples were also studied. (C) 2004 Elsevier B.V. All rights reserved.</p>10aCeramics10aElectron microscopy10aferroelectricity10aOxides1 aDhage, S., R.1 aPasricha, R.1 aRavi, V.  uhttps://library.ncl.res.in/content/synthesis-sr05ba05nb2o6-urea-method-001462nas a2200241   4500008004100000022001400041245007900055210006900134260006900203300001200272490000700284520066300291653001300954653002300967653002400990653002101014653001101035100001801046700001701064700002101081700001301102856010501115       2006                        eng d  a0254-058400aCo-precipitation technique for the preparation of ferroelectric BaBi2Ta2O90 aCoprecipitation technique for the preparation of ferroelectric B  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcAUG  a344-3460 v983 a<p>A simple co-precipitation technique had been successfully applied for the preparation of pure ultrafine single phase BaBi2Ta2O9 (BBT). Ammonium hydroxide and ammonium oxalate were used to precipitate Ba2+, Bi3+ and Ta5+ cations simultaneously. No pyrochlore phase was found while heating powder at 800 degrees C and pure BaBi2Ta2O9 phase was found to be formed by X-ray diffraction. Particle size and morphology was studied by transmission electron spectroscopy (TEM). The room temperature dielectric constant at 1 kHz is 350. The ferroelectric hysteresis loop parameters of these samples were also studied. (c) 2005 Elsevier B.V. All rights reserved.</p>10aCeramics10aChemical synthesis10aelectronic material10aferroelectricity10aOxides1 aDhage, S., R.1 aPasricha, R.1 aMurugan, Vadivel1 aRavi, V.  uhttps://library.ncl.res.in/content/co-precipitation-technique-preparation-ferroelectric-babi2ta2o9-001460nas a2200217   4500008004100000022001400041245004500055210004500100260009900145300001200244490000700256520078700263653002301050653001901073653001801092653000801110100001801118700001901136700001301155856007401168       2007                        eng d  a0272-884200aInfluence of surfactant on ZnO varistors0 aInfluence of surfactant on ZnO varistors  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcMAR  a289-2910 v333 a<p>ZnO varistors with and without surfactant such as sodium dodecyl sulphate (SIDS) are prepared by nitrate-combustion process. The samples were identically heat treated and sintered at 1000 degrees C for 12 h to study the influence of the surfactant on the nonlinear electrical properties of polycrystalline ZnO. It is observed that the nonlinear coefficient decreases marginally (alpha = 35) for samples prepared with surfactant, whereas breakdown field (E-B = 130 V/mm) decreased significantly. The corresponding parameters for the samples synthesized without surfactant are alpha = 45 and E-B = 400 V/mm. Hence, this method can be used for the manufacture of varistors with low to moderate breakdown fields. (c) 2005 Elsevier Ltd and Techna Group S.r.l. All rights reserved.</p>10aChemical synthesis10aSemiconductors10aX-ray methods10aZnO1 aDhage, S., R.1 aNavale, S., C.1 aRavi, V.  uhttps://library.ncl.res.in/content/influence-surfactant-zno-varistors01209nas a2200229   4500008004100000022001400041245004800055210004800103260006100151300001200212490000700224520051500231653002300746653002500769653001900794653001400813653002200827100001800849700001300867700001700880856008200897       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<p>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.</p>10aChemical synthesis10aelectronic materials10aMicrostructure10atin oxide10aX-ray diffraction1 aDhage, S., R.1 aRavi, V.1 aYang, O., B.  uhttps://library.ncl.res.in/content/low-voltage-varistor-ceramics-based-sno2-001543nas a2200205   4500008004100000022001400041245010300055210006900158260006900227300001200296490000800308520078200316653002001098653003301118653001401151100001801165700001301183700001701196856012401213       2008                        eng d  a0925-838800aVaristor property of SnO2 center dot CoO center dot Ta2O5 ceramic modified by barium and strontium0 aVaristor property of SnO2 center dot CoO center dot Ta2O5 cerami  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcOCT  a483-4870 v4663 a<p>The influence of an alkali earth (Ba/Sr) element in small quantities (&lt; 1 at.%) on non-linear electrical properties of 98.5% SnO2 + 1% CoO + 0.5% Ta2O5 (all in at.%) varistor system has been investigated. The non-linear coefficient increases from 33 to 52 whereas breakdown field strength varies 5025-6050 V cm(-1) for the barium-doped samples. In case of strontium-doped specimens moderate increase in non-linear coefficient but significant increase in breakdown field is observed. It is proposed that due to ionic size misfit, Ba and Sr segregates to grain boundaries thereby modifying their barrier properties. The contribution from grain boundary phase to the electrical property is confirmed by the impedance analysis. (C) 2007 Elsevier B.V. All rights reserved.</p>10aOxide materials10ascanning electron microscopy10aSintering1 aDhage, S., R.1 aRavi, V.1 aYang, O., B.  uhttps://library.ncl.res.in/content/varistor-property-sno2-center-dot-coo-center-dot-ta2o5-ceramic-modified-barium-and-0