@article { ISI:000228794300014, title = {Preparation of fine MgTa2O6 and Mg4Ta2O9 powders by chemical methods}, journal = {Materials Science and Engineering B-Solid State Materials for Advanced Technology}, volume = {119}, number = {2}, year = {2005}, month = {MAY}, pages = {189-191}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Two different chemical methods are applied to prepare MgTa2O6 (MT2) and Mg4Ta2O9 (M4T2) powders. A gel was formed when a aqueous solution of Mg(NO3)(2), TAF(5) and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 750 degrees C produced the fine crystallites of ternary oxide, M4T2. A simple co-precipitation technique had been successfully applied for the preparation of pure ultrafine single phase MT2. Ammonium hydroxide was used to precipitate Mg2+ and Ta5+ cations as hydroxides simultaneously. This precursor on heating at 750 degrees produces MT2 powders. The phase contents and lattice parameters were studied by the powder X-ray diffraction (XRD). Particle size and morphology was studied by transmission electron microscopy (TEM). (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Electron microscopy, powders-chemical preparation, X-ray methods}, issn = {0921-5107}, doi = {10.1016/j.mseb.2005.02.058}, author = {Navale, SC and Ravi, V} } @article { ISI:000228253200008, title = {Preparation of nanocrystalline ferroelectric BaNb(2)O6 by citrate gel method}, journal = {Bulletin of Materials Science}, volume = {28}, number = {2}, year = {2005}, month = {APR}, pages = {121-123}, publisher = {INDIAN ACADEMY SCIENCES}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

A gel was formed when a aqueous solution of BaCl2, NbF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 600 degrees C yielded the nano crystallites of BaNb2O6, as confirmed by X-ray diffraction study (XRD). This is a much lower temperature as compared to that prepared by traditional solid state method (1000 degrees C) as reported for the formation of BaNb2O6. Transmission electron microscopic. (TEM) investigations revealed that the average particle size is 50 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found to be 1000. The ferroelectric hysteresis loop parameters of these samples were also studied.

}, keywords = {Ceramics, Chemical synthesis, electronic material, ferroelectricity, Oxides}, issn = {0250-4707}, doi = {10.1007/BF02704230}, author = {Gaikwad, S. P. and Samuel, V and Pasricha, R and Ravi, V} } @article { ISI:000230877900002, title = {Preparation of nanocrystalline ferroelectric CaBi2Ta2O9 by the urea method}, journal = {Ceramics International}, volume = {31}, number = {6}, year = {2005}, month = {JAN }, pages = {773-775}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

A precipitate was formed when a aqueous solution of CaCl2, BiCl3, TaF5 and urea in stoichiometric ratio (total metal cations to urea ratio is 5) is heated on a water bath. This precipitate on decomposition at 600 degrees C yielded the nanocrystallites of ternary oxide CaBi2Ta2O9 (CBT) as confirmed by X-ray diffraction (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). Ferroelectric hysteresis loop parameters such as remnant polarization (P-r) and coercive field (E-C) were also determined. TEM investigations revealed that the average particle size of the polycrystalline powder is 70 nm. The room temperature dielectric constant was found to be 110. (c) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

}, keywords = {dielectric properties, Electron microscopy, ferroelectric properties, powders : chemical preparation}, issn = {0272-8842}, doi = {10.1016/j.ceramint.2004.08.011}, author = {Gaikwad, S. P. and Pasricha, R and Ravi, V} } @article { ISI:000227447800010, title = {Preparation of nanocrystalline ferroelectric CaBi2TaO9 by citrate gel method}, journal = {Materials Science and Engineering B-Solid State Materials for Advanced Technology}, volume = {117}, number = {2}, year = {2005}, month = {MAR}, pages = {159-161}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

A gel was formed when an aqueous solution of CaCl2, BiCl3, TaF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 600degreesC yielded the nano-crystallites of ternary oxide, CaBi2Ta2O9 (CBT) as confirmed by X-ray diffraction study (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). Ferroelectric hysteresis loop parameters such as remnant polarization (P-r) and coercive field (E-C) are also determined. TEM investigations revealed that the average particle size of the polycrystalline powder is 40 nm. The room temperature dielectric constant was found to be 90. (C) 2004 Elsevier B.V All rights reserved.

}, keywords = {Bismuth, diffraction, Electron microscopy}, issn = {0921-5107}, doi = {10.1016/j.mseb.2004.11.006}, author = {Gaikwad, S. P. and Pasricha, R and Ravi, V} } @article { ISI:000230275100022, title = {Preparation of nanocrystalline LiNbO3 by citrate gel method}, journal = {Materials Letters}, volume = {59}, number = {19-20}, year = {2005}, month = {AUG}, pages = {2476-2478}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A gel was formed when an aqueous solution of Li(NO3) NbF5 and citric acid in stoichiometric ratio is heated in a water bath at 100 degrees C. This gel on decomposition at 700 degrees C produced the fine crystallites of ternary oxide, LiNbO3 (LN). The phase contents and lattice parameters were studied by the powder X-ray diffraction (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Ceramics, Electron microscopy, electronic materials, lithium niobate, X-ray diffraction}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.03.028}, author = {Navale, SC and Samuel, V and Ravi, V} } @article { ISI:000229379000010, title = {Preparation of nanocrystalline MgNb2O6 by citrate gel method}, journal = {Materials Letters}, volume = {59}, number = {17}, year = {2005}, month = {JUL}, pages = {2146-2148}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A gel was formed when a aqueous solution of Mg(NO3)(2), NbF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 700 degrees C produced the fine crystallites of ternary oxide, MgNb2O6 (MN). The formation of MN phase and lattice parameters were determined by the powder X-ray diffraction (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Citrate gel, Electron microscopy, magnesium niobate, powders, X-ray diffraction}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.02.050}, author = {Pasricha, R and Ravi, V} } @article { ISI:000231605600002, title = {Preparation of ultrafine LiTaO3 powders by citrate gel method}, journal = {Bulletin of Materials Science}, volume = {28}, number = {5}, year = {2005}, month = {AUG}, pages = {391-393}, publisher = {INDIAN ACADEMY SCIENCES}, type = {Article}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

A gel was formed when a aqueous solution of Li(NO3), TaF5 and citric acid in stoichiometric ratio was heated in a water bath. This gel on decomposition at 700 degrees C produced fine crystallites of ternary oxide, LiTaO3 (LT). The phase contents and lattice parameters were studied by powder X-ray diffraction (XRD). Particle size and morphology were studied by transmission electron spectroscopy (TEM).

}, keywords = {Ceramics, Electron microscopy, electronic materials, X-ray diffraction}, issn = {0250-4707}, doi = {10.1007/BF02711224}, author = {Navale, SC and Samuel, V and Ravi, V} }