@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:000234951400014, title = {Coprecipitation technique to prepare LiTaO3 powders}, journal = {Materials Letters}, volume = {60}, number = {8}, year = {2006}, month = {APR}, pages = {1047-1048}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A simple coprecipitation technique had been successfully applied for the preparation of pure ultrafine single phase LiTaO3 (LT). An aqueous mixture of ammonium carbonate and ammonium hydroxide was used to precipitate Li+ and Ta5+ cations as carbonate and hydroxide respectively. This precursor oil heating at 750 degrees C produces LT powders. For comparison, LT 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). (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Ceramics, Electron microscopy, electronic materials, X-ray diffraction}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.10.074}, author = {Navale, SC and Gaikwad, A. B. and Ravi, V} } @article { ISI:000237439300005, title = {Coprecipitation technique to prepare NaNbO3 and NaTaO3}, journal = {Bulletin of Materials Science}, volume = {29}, number = {2}, year = {2006}, month = {APR}, pages = {123-125}, publisher = {INDIAN ACADEMY SCIENCES}, type = {Article}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

A simple coprecipitation technique has been used successfully for the preparation of pure, ultrafine, single phases of NaNbO3 (NN) and NaTaO3 (NT). An alcoholic solution of ammonium carbonate and ammonium hydroxide was used to precipitate Na+ and Nb5+ (or Ta5+) cations under basic conditions as carbonate and hydroxide, respectively. On heating at 700 degrees C, these precursors produce respective products. For comparison, both NN and NT powders were also prepared by the traditional solid state method. The phase purity and lattice parameters were studied by powder X-ray diffraction (XRD). The particle size and morphology were studied by scanning electron microscopy (SEM).

}, keywords = {Ceramics, Chemical synthesis, Electron microscopy, electronic materials, Oxides, X-ray methods}, issn = {0250-4707}, doi = {10.1007/BF02704604}, author = {Samuel, V and Gaikwad, A. B. and Ravi, V} } @article { ISI:000238866300004, title = {Coprecipitation technique to prepare Sr0.5Ba0.5Nb2O6}, journal = {Bulletin of Materials Science}, volume = {29}, number = {3}, year = {2006}, month = {JUN}, pages = {221-223}, publisher = {INDIAN ACADEMY SCIENCES}, type = {Article}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

An aqueous mixture of ammonium oxalate and ammonium hydroxide was used to coprecipitate barium and strontium ions as oxalates and niobium ions as hydroxide under basic conditions. This precursor on calcining at 750 degrees C yielded Sr0.5Ba0.5Nb2O6 phase. This is a much lower temperature than that prepared by traditional solid state method (1000 degrees C) as reported for the formation of Sr0.5Ba0.5Nb2O6 (SBN). Transmission electron microscopic (TEM) investigations revealed that the average particle size was 80 nm for the calcined powders. The room temperature dielectric constant at I kHz was found to be 1100. The ferroelectric hysteresis loop parameters of these samples were also studied.

}, keywords = {Ceramics, Electron microscopy, ferroelectricity, Oxides, X-ray diffraction}, issn = {0250-4707}, doi = {10.1007/BF02706488}, author = {Murugan, A. Vadivel and Gaikwad, A. B. and Samuel, V. 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:000242511300022, title = {Adsorption of methanol on mesoporous SBA-15}, journal = {Materials Letter}, volume = {61}, number = {1}, year = {2007}, month = {JAN}, pages = {88-92}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The adsorption of methanol onmesoporous SBA-15 has been studiedbyrising Brunauer-Emmett-Teller (BET) surface area analysis, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoclectrom spectroscopy (XPS) and tbennogravimettic analysis (TGA). The BET surface area analysis shows decreases of the surface area from 387 to 383 m(2)/g, pore volume from 0.88 to 0.81 cm(3)/g and pore diameter from 9.07 to 8.4 mm after methanol adsorption. The appearance of strong IR bands at 2862 and 2964cm(-1) due to methyl (-CH3) symmetric and asymmetric stretching demonstrate the presence of methanol and evidence of successful methanol adsorption. XPS results show increase of carbon and oxygen content on the surface of SBA-15. Thermogravirriettic analysis shows that the methanol adsorbed on SBA-15 is stable up to a temperature of 265 degrees C and that the methanol adlayers decompose between 265 and 588 degrees C. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Adsorption, Electron microscopy, Methanol, SBA-15, Surfaces, thermal stability}, issn = {0167-577X}, doi = {10.1016/j.matlet.2006.04.012}, author = {Mirji, S. A. and Halligudi, Shivaraj B. and Mathew, Nevin T. and Jacob, Nalini E. and Patil, K. R. and Gaikwad, A. B.} } @article { ISI:000244008300030, title = {Co-precipitation technique to prepare BaTa2O6}, journal = {Ceramics International}, volume = {33}, number = {2}, year = {2007}, month = {JAN}, pages = {297-299}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

A mixture of ammonium oxalate and ammonium hydroxide was used to co-precipitate barium and tantalum ions as barium oxalate and tantalum hydroxide under basic conditions. On calcination at 750 degrees C, this precursor yielded BaTa2O6 (BT) ceramics. This is much lower temperature as compared to that prepared by traditional solid-state method (1000 degrees C) as reported for the formation of BaTa206. Transmission electron microscope (TEM) investigations revealed that the average particle size is 70 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found to be 100. (c) 2005 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

}, keywords = {barium tantalate, Ceramics, Electron microscopy, Oxides, X-ray diffraction}, issn = {0272-8842}, doi = {10.1016/j.ceramint.2005.08.012}, author = {Navale, S. C. and Samuel, Violet and Gaikwad, A. B. 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: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:000246260000011, title = {Preparation of nanocrystalline ferroelectric CaBi4Ti4O15 by citrate gel method}, journal = {Ceramics International}, volume = {33}, number = {4}, year = {2007}, month = {JAN}, pages = {569-571}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

A gel was formed when an aqueous solution of CaCl2, BiNO3, TiOCl2 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 700 degrees C produced nano crystallites of the ternary oxide, CaBi4Ti4O15 (CBT). 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). The room temperature dielectric constant at 1 kHz is 390. The ferroelectric hysteresis loop parameters of these samples were also studied by a home-built Sawyer-tower circuit. (c) 2006 Elsevier Ltd and Techna Group S.H. All rights reserved.

}, keywords = {Ceramics, Chemical synthesis, Electron microscopy, Oxides, X-ray methods}, issn = {0272-8842}, doi = {10.1016/j.ceramint.2005.11.006}, author = {Murugan, A. Vadivel and Gaikwad, A. B. and Samuel, V. and Ravi, V.} } @article { ISI:000255612400002, title = {Preparation of ferroelectric CaBi(4)Ti(4)O(15) powders from novel hydroxide precursors}, journal = {Materials Letters}, volume = {62}, number = {12-13}, year = {2008}, month = {APR}, pages = {1751-1753}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Ferroelectric CaBi(4)Ti(4)O(15) (CBT) powders were prepared for the first time from their respective hydroxides. Commercially purchased Ca(OH)(2) is mixed thoroughly with freshly prepared Bi(OH)(3) and Ti(OH)(4) in stoichiometrie ratio and heated at different temperatures ranging from 100 to 600 degrees C. The CBT phase found to be formed at 500 degrees C by the X-ray diffraction studies. This is the lowest temperature so far reported in the literature for the formation of CBT phase. The advantage of this method is that it also avoids the formation of calcium carbonate phase during synthesis. The phase contents and lattice parameters were studied by the powder X-ray diffraction (XRD) method. The average particle size and morphology were studied by scanning electron microscopy (SEM) technique. (c) 2007 Elsevier B.V All rights reserved.

}, keywords = {CaBi(4)Ti(4)O(15), Ceramics, Chemical synthesis, Electron microscopy, Oxides, X-ray methods}, issn = {0167-577X}, doi = {10.1016/j.matlet.2007.09.080}, author = {Deshmukh, Rupali G. and Vaishampayan, Mukta V. and Darshane, Sonali L. and Mulla, Imtiaz S. and Gaikwad, A. B. and Rao, N. Kotaserwara and Ravi, V.} }