@article { ISI:000228797100048, title = {Preparation of ferroelectric BaNb2O6 the urea method}, journal = {Materials Letters}, volume = {59}, number = {14-15}, year = {2005}, month = {JUN}, pages = {1929-1931}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

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.

}, keywords = {Ceramics, Chemical synthesis, electronic material, ferroelectricity, Oxides}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.02.028}, author = {Dhage, S. R. and Pasricha, R. and Ravi, V.} } @article { ISI:000237158200003, title = {Phase evolution of NiTiO3 prepared by coprecipitation method}, journal = {Materials Letters}, volume = {60}, number = {15}, year = {2006}, month = {JUL}, pages = {1791-1792}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A simple coprecipitation technique was used for the preparation of NiTiO3 powders. Ammonium carbonate solution was added to a solution mixture containing stoichiometric amounts of Ni(NO3)(2) and TiOCl2 to precipitate nickel as carbonate and titanium as hydroxide under basic conditions. The precipitate was calcined at different temperatures ranging from 100 to 800 degrees C and phase evolution of NiTiO3 was investigated by X-ray diffraction (XRD) studies. It is observed that nickel titanate was formed at 750 degrees C. For comparison, NiTiO3 was also prepared by standard ceramic process. Particle size and morphology was studied by transmission electron microscopy (TEM). (c) 2005 Elsevier B.V. All fights reserved.

}, keywords = {Ceramics, Chemical synthesis, Electron microscopy, NiTiO3, Oxides, X-ray diffraction}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.12.023}, author = {Murugan, A. Vadivel and Samuel, V. and Navale, S. C. and Ravi, V.} } @article { ISI:000240680300119, title = {Photoluminescence studies of Eu3+ doped Y2O3 nanophosphor prepared by microwave hydrothermal method}, journal = {Applied Physics Letters}, volume = {89}, number = {12}, year = {2006}, month = {SEP}, pages = {123120}, publisher = {AMER INST PHYSICS}, type = {Article}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

In this letter, the authors report the photoluminescence studies of Eu3+ doped Y2O3 nanorods, which have been synthesized by rapid microwave hydrothermal route within 6 min. The nanostructured Eu3+ doped Y2O3 is characterized by x-ray diffraction, transmission electron microscopy, and photoluminescence. The emission spectrum shows transitions from the excited 5D(0) state to F-7(J) (J=0,1,2,3,4) levels of the Eu3+ ion. The most intense peak around 612 nm is due to the D-5(0)-\> F-7(2) transition, expected from the Judd-Ofelt selection rules [B. R. Judd, Phys. Rev. 127, 750 (1962); G. S. Ofelt, J. Chem. Phys. 37, 511 (1962)]. Photoluminescence measurements demonstrated that the nanocrystalline Eu3+:Y2O3 phase shows higher photoluminescence intensity. (c) 2006 American Institute of Physics.

}, issn = {0003-6951}, doi = {10.1063/1.2356694}, author = {Murugan, A. Vadivel and Viswanath, Annamraju Kasi and Ravi, V. and Kakade, Bhalchandra A. and Saaminathan, V.} } @article { ISI:000234951400008, title = {Preparation of nanocrystalline ferroelectric BaBi4Ti4O15 by Pechini method}, journal = {Materials Letters}, volume = {60}, number = {8}, year = {2006}, month = {APR}, pages = {1023-1025}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A gel was formed when an aqueous solution of BaCl2, BiNO3, TiOCl2 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 600 degrees C produced the nano crystallites of ternary oxide, BaBi4Ti4O15 (BBT). 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 I KHz is 90. The ferroelectric hysteresis loop parameters of these samples were also studied by a home built Sawyer-tower circuit. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {dielectric properties, Electron microscopy, ferroelectric properties, powders chemical preparation}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.10.068}, author = {Murugan, A. Vadivel and Navale, S. C. 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.} }