@article { ISI:000227550500009, title = {Co-precipitation method for the preparation of nanocrystalline ferroelectric SrBi2Nb2O9 ceramics}, journal = {Journal of Electroceramics}, volume = {14}, number = {1}, year = {2005}, month = {JAN}, pages = {83-87}, publisher = {SPRINGER}, type = {Article}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

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.

}, keywords = {Ceramics, Chemical synthesis, electronic materials, ferroelectricity, Oxides}, issn = {1385-3449}, doi = {10.1007/s10832-005-6588-y}, author = {Gaikwad, S. P. and Dhage, S. R. and Potdar, H. S. and Samuel, V. and Ravi, V.} } @article { ISI:000229811300003, title = {Coprecipitation technique to prepare ZnM2O6 powders}, journal = {Bulletin of Materials Science}, volume = {28}, number = {3}, year = {2005}, month = {JUN}, pages = {205-207}, publisher = {INDIAN ACADEMY SCIENCES}, type = {Article}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

A simple coprecipitation technique was successfully applied for the preparation of pure ultrafine single phase, ZnNb2O6 (ZN). Ammonium hydroxide was used to precipitate Zn2+ and Nb5+ cations as hydroxides simultaneously. This precursor on heating at 750 degrees, produced ZN powders. For comparison, ZN powders were also prepared by the traditional solid state method. The phase contents and lattice parameters were studied by the 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/BF02711248}, author = {Deshpande, V. V. and Patil, M. M. and Navale, S. C. and Ravi, V.} } @article { ISI:000235860500029, title = {Chemical methods to synthesize FeTiO3 powders}, journal = {Materials Letters}, volume = {60}, number = {11}, year = {2006}, month = {MAY}, pages = {1425-1427}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Three different techniques were used to synthesize FeTiO3 powders. The first method is simple coprecipitation of both Fe and Ti ions under basic conditions using standard ammonia solution from aqueous ferric nitrate and titanium oxy chloride. This precipitate on heating at 400 degrees C produces ilmenite phase. The second method is to digest hydroxide precipitates at 100 degrees C to form FeTiO3 phase. The third technique is to make use of citrate process to form FeTiO3 powders. The phase contents and lattice parameters were Studied by powder X-ray diffraction (XRD). Particle size and morphology were studied by Transmission Electron Microscopy (TEM). (c) 2005 Elsevier B.V. All tights reserved.

}, keywords = {Chemical synthesis, Electron microscopy, electronic materials, X-ray methods}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.11.041}, author = {Mona, J. and Kale, Sangeeta N. and Gaikwad, A. B. and Murugan, A. Vadivel and Ravi, V.} } @article { ISI:000238624000017, title = {Synthesis of MgNb2O6 by coprecipitation}, journal = {Materials Research Bulletin}, volume = {41}, number = {7}, year = {2006}, month = {JUL}, pages = {1353-1356}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A simple coprecipitation technique was used successfully to synthesize fine powders of MgNb2O6 (MN) phase. An aqueous mixture of ammonium carbonate and ammonium hydroxide was used to precipitate Mg2+ and Nb5+ cations as carbonate and hydroxide respectively under basic conditions. This precipitate on heating at 750 degrees C produced MN powders. For comparison MN powders were prepared by the traditional solid state method. The phase content and the lattice parameters were studied by powder X-ray diffraction (XRD). Particle size and morphology of the particles were studied by scanning electron microscopy (SEM). (C) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {Ceramics, Chemical synthesis, Electron microscopy, electronic materials, X-ray diffraction}, issn = {0025-5408}, doi = {10.1016/j.materresbull.2005.12.009}, author = {Navale, S. C. and Gaikwad, A. B. and Ravi, V.} } @article { ISI:000246158300001, title = {Coprecipitation technique to prepare CoTa2O6 and CoNb2O6}, journal = {Materials Letter}, volume = {61}, number = {11-12}, year = {2007}, month = {MAY}, pages = {2127-2129}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

An aqueous solution of sodium hydroxide was used to coprecipitate cobalt and tantalum (or niobium) ions from their precursors as hydroxides under basic conditions. This precipitate yielded CoTa2O6 (CT) or CoNb2O6 (CN) ceramics on calcining at 700 degrees C, i.e. at a temperature much lower than 900 degrees C, reported for the formation of these powders prepared by the traditional solid state method. The X-ray diffraction (XRD) studies were employed to investigate phase contents and lattice parameters. The morphology of the synthesized powders was investigated by transmission electron microscopy (TEM). (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, electronic materials, Oxides, X-ray methods}, issn = {0167-577X}, doi = {10.1016/j.matlet.2006.08.024}, author = {Mulla, Imtiaz S. and Natarajan, N. and Gaikwad, A. B. and Samuel, V. and Guptha, U. N. and Ravi, V.} } @article { ISI:000246158300058, title = {Coprecipitation technique to prepare NiNb2O6}, journal = {Materials Letter}, volume = {61}, number = {11-12}, year = {2007}, month = {MAY}, pages = {2354-2355}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A mixture of ammonium carbonate and ammonium hydroxide was used to coprecipitate nickel and niobium ions as nickel carbonate and niobium hydroxide under basic conditions. This precursor yielded NiNb2O6 (NN) ceramics on calcining at 700 degrees C (at a temperature lower than 800 degrees C which is necessary for the formation of NiNb2O6 when prepared by the traditional solid state method). The average particle size and morphology of these powders were investigated by transmission electron microscope (TEM). (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, Electron microscopy, electronic materials, Oxides, X-ray methods}, issn = {0167-577X}, doi = {10.1016/j.matlet.2006.09.010}, author = {Samuel, V. and Gaikwad, A. B. and Jadhav, A. D. and Natarajan, N. and Ravi, V.} } @article { ISI:000252474200009, title = {Low voltage varistor ceramics based on SnO2}, journal = {Bulletin of Materials Science}, volume = {30}, number = {6}, year = {2007}, month = {DEC}, pages = {583-586}, publisher = {SPRINGER}, type = {Article}, address = {233 SPRING STREET, NEW YORK, NY 10013 USA}, abstract = {

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.

}, keywords = {Chemical synthesis, electronic materials, Microstructure, tin oxide, X-ray diffraction}, issn = {0250-4707}, doi = {10.1007/s12034-007-0092-8}, author = {Dhage, S. R. and Ravi, V. and Yang, O. B.} } @article { ISI:000243164000035, title = {Novel technique to prepare LiNbO3 at low temperature}, journal = {Materials Letter}, volume = {61}, number = {3}, year = {2007}, month = {FEB}, pages = {765-766}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Fresh niobium hydroxide was first precipitated from NbF5 solution using an aqueous ammonium hydroxide under basic conditions. Then a simple procedure of mixing lithium and niobium hydroxides together and heating at a low temperature (400 degrees C) produced pure ultrafine single phase LiNbO3 (LN). In the literature, this is the lowest temperature so far reported on the formation of LN. The phase content and lattice parameters are determined by X-ray diffraction (XRD). The average particle size and morphology were studied by transmission electron microscopy (TEM). (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, Electron microscopy, electronic materials, LiNbO3, X-ray diffraction}, issn = {0167-577X}, doi = {10.1016/j.matlet.2006.05.056}, author = {Samuel, V. and Gaikwad, A. B. and Jadhav, A. D. and Mirji, S. A. and Ravi, V.} } @article { ISI:000253106100026, title = {Low temperature synthesis of SrNb2O6 and SrTa2O6 using hydroxide precursor}, journal = {Materials Letters}, volume = {62}, number = {6-7}, year = {2008}, month = {MAR}, pages = {892-894}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

SrNb2O6 (SN) or SrTA(2)O(6) (ST) compounds were prepared at low temperatures for the first time from hydroxide precursors. A simple procedure of mixing commercially purchased strontium hydroxide and niobium (or tantalum) hydroxide thoroughly together and heating at a low temperature (\<400 degrees C) produced SrNb2O6 (SN) or SrTa2O6 (ST) powders. This is the lowest temperature so far reported for the formation of these phases. These materials are potential candidates for ferroelectric and electro-optic applications. The reaction sequence and evolution of the phase formation were investigated by X-ray diffraction (XRD) studies. The average particle size and morphology of these powders were studied by scanning electron microscopy (SEM). (C) 2007 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, Electron microscopy, electronic materials, X-ray diffraction}, issn = {0167-577X}, doi = {10.1016/j.matlet.2007.07.006}, author = {Muthurajan, H. and Kumar, H. H. and Koteswara Rao, N. and Pradhan, Sivaram and Jha, Ratnesh Kumar and Ravi, V.} } @article { ISI:000254698300033, title = {Novel technique to prepare LiTaO3 at low temperature}, journal = {Ceramics International}, volume = {34}, number = {3}, year = {2008}, month = {APR}, pages = {669-670}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

Firstly, fresh tantalum hydroxide was precipitated from TaF5 solution using an aqueous ammonium hydroxide under basic conditions. Then a simple procedure of mixing lithium and tantalum hydroxides together and heating at a low temperature (450 degrees C) produced pure ultrafine single phase LiTaO3 (LT). This is the lowest temperature so far reported for the formation of LT in the literature. The phase content and lattice parameters are determined by X-ray diffraction (XRD). The average particle size and morphology were studied by transmission electron microscopy (TEM). (c) 2006 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

}, keywords = {chemical synthesis X-ray diffraction, Electron microscopy, electronic materials, LiTaO3}, issn = {0272-8842}, doi = {10.1016/j.ceramint.2006.11.003}, author = {Muthurajan, H. and Kumar, H. H. and Natarajan, N. and Ravi, V.} }