@article { ISI:000254698300035, title = {Co-precipitation method for preparation of Bi3TiNbO9 powders}, journal = {Ceramics International}, volume = {34}, number = {3}, year = {2008}, month = {APR}, pages = {675-677}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

A simple co-precipitation technique has been successfully used for the preparation of pure, ultrafine, single phase Bi3TiNbO9 (BTN). An aqueous ammonium hydroxide solution was used to simultaneously precipitate Bi3+, Ti4+ and Nb5+, cations as hydroxides under basic conditions (pH similar to 9). No pyrochlore phase was found while heating powder at 500 degrees C and pure BTN phase was found to be formed by X-ray diffraction (XRD). For comparison, BTN samples were also synthesized by the traditional solid state method. The sequence of phase formation in both cases were investigated by XRD studies. (c) 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

}, keywords = {Ceramics, Chemical synthesis, electronic material, Oxides, XRD}, issn = {0272-8842}, doi = {10.1016/j.ceramint.2007.02.002}, author = {Gupta, U. N. and Samuel, V. and Muthurajan, H. and Kumar, H. H. and Patil, S. D. and Ravi, V.} } @article { ISI:000257538200034, title = {Co-precipitation technique to prepare BiNbO4 powders}, journal = {Ceramics International}, volume = {34}, number = {6}, year = {2008}, month = {AUG}, pages = {1565-1567}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

A simple co-precipitation technique was successfully used for the preparation of pure ultrafine single phase BiNbO4. A standard ammonium hydroxide solution was used to precipitate Bi3+ and Ta5+ cations as hydroxides simultaneously under basic conditions. For comparison, BN powders were also prepared by the traditional solid-state method. It is observed that the co-precipitation technique produces BiNbO4 on heating at 600 degrees C, whereas complete phase formation occurs only at 800 degrees C in the solid-state method. The phase contents and lattice parameters were Studied by powder X-ray diffraction (XRD). (C) 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

}, keywords = {BiNbO4, Ceramics, Chemical synthesis, Electron microscopy, Oxides, X-ray diffraction}, issn = {0272-8842}, doi = {10.1016/j.ceramint.2007.03.022}, author = {Radha, R. and Gupta, U. N. and Samuel, V. and Muthurajan, H. and Kumar, H. H. 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:000257365900027, title = {Novel hydroxide precursors for low temperature synthesis of selected ternary oxides}, journal = {Materials Research Bulletin}, volume = {43}, number = {7}, year = {2008}, month = {JUL}, pages = {1842-1849}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A novel method of using hydroxide precursors to reduce the synthesis temperature for few selected ternary oxides has been presented here. This technique is very useful and advantageous when the ternary oxides contain an alkaline earth element. The selected compositions for this method are BaCeO3 (BC), BaBiO3 (BB), La0.7Sr0.3CoO3 (LSCO) and BaBi2Nb2O9 (BBN). Commercially purchased strontium (or barium) hydroxide and freshly prepared lanthanum, cobalt, bismuth and niobium hydroxides were mixed thoroughly in stoichiometric ratio and heated at different temperatures ranging from 100 to 700 degrees C for 10 h for corresponding compositions. The sequence of the reaction and evolution of the product phase were studied by the X-ray diffraction (XRD) studies. The phase purity and lattice parameters were also determined by XRD investigations. All the product phases in each case were formed at relatively low temperature than when they were prepared by co-precipitation or solid state method. The morphology and average particle size of these powders were investigated by scanning electron microscopy (SEM). (C) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {Ceramics, Chemical synthesis, Electron microscopy, Oxides, X-ray diffraction}, issn = {0025-5408}, doi = {10.1016/j.materresbull.2007.07.006}, author = {Muthurajan, H. and Rao, N. Koteswara and Gupta, U. N. and Pradhan, Sivaram and Jha, Ratnesh Kumar and Kumar, H. H. and Mirji, S. A. and Ravi, V.} }