@article { ISI:000233914500027, title = {Synthesis of CdS and alloyed CdMnS nanocrystals using aqueous foams}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {5}, number = {12}, year = {2005}, month = {DEC}, pages = {2144-2154}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA}, abstract = {

Certain surfactant-stabilized aqueous foams provide a potentially efficient and simple chemical route for the synthesis of various nanomaterials with controllable structure, size, and shape. In the present work, a one-step process for the synthesis of CdS and Cdl(1-x)Mn(x)S (0 \< x \< 10) nanocrystals has been described. Aqueous CdCl2 and the aerosol-OT solutions are homogeneously mixed together and thereafter, nitrogen is bubbled through this solution to produce stable aqueous foam. After drainage of the foam, the freestanding dry foam consisting of cadmium cations electrostatically complexed with the anionic aerosol-OT molecules at the liquid-gas interface is treated with H2S vapor. The foam turns yellowish-orange and collapses, in the process yielding CdS nanoclusters of variable morphology. This morphology variation is appropriately attributed to growth of the CdS as well as alloyed Cd1-xMnxS nanoparticles in different regions of the foam contributing to the varying topological structure. Optical absorption spectra of both CdS and Cd1-xMnxS nanoparticles clearly show a well-defined exciton absorption feature around 450 nm due to quantum confinement effects. The interesting band edge emission characteristics of these AOT-capped CdS and Cd1-xMnxS nanoparticles produced in the foam are discussed with respect to their size and shape. Particular interest in the present novel aqueous foam approach arises due to the fact that the cubic zincblende CdS and alloyed Cd1-xMnxS nanocrystals could easily be obtained even under ambient experimental conditions itself.

}, keywords = {absorption and fluorescence, aerosol-OT, alloyed CdMnS nanocrystals, aqueous foams, CdS nanoclusters, quantum confinement, zincblende}, issn = {1533-4880}, doi = {10.1166/jnn.2005.401}, author = {Kumar, P. Senthil and Kasture, Manasi and Raghavan, U and Pasricha, R and Sastry, M} } @article { ISI:000228771600009, title = {Synthesis of nanocrystalline rutile}, journal = {Ceramics International}, volume = {31}, number = {4}, year = {2005}, month = {JAN}, pages = {555-557}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

Nanocrystalline titanium dioxide (TiO2) in the rutile phase has been obtained by homogeneous precipitation using urea and TiOCl2. A mixture of urea and TiOCl2 is heated on a hot water bath at 65-75 degrees C to precipitate rutile powders. X-ray diffraction (XRD) studies on these oven-dried powders indicated the formation of single-phase rutile. Raman scattering experiments were also performed to confirm the formation of the rutile phase. Transmission electron microscopy (TEM) investigations revealed the average particle size of these powders to be 40 nm. (c) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

}, keywords = {chemical preparation, Electron microscopy, powders, TiO2, X-ray methods}, issn = {0272-8842}, author = {Samuel, V and Pasricha, R and Ravi, V} } @article { ISI:000231592300006, title = {Synthesis of Sr0.5Ba0.5Nb2O6 by citrate gel method}, journal = {Materials Chemistry and Physics}, volume = {94}, number = {1}, year = {2005}, month = {NOV}, pages = {34-36}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

A gel was formed when an aqueous solution of BaCl2, SrCl2, NbF5 and citric acid in stoichiometric ratio is heated on a water bath. This gel on decomposition at 700 degrees C yielded the nanocrystallites of ternary oxide, Sr0.5Ba0.5Nb2O6 (SBN) as confirmed by X-ray diffraction study (XRD). Particle size and morphology was studied by transmission electron spectroscopy (TEM). The room temperature dielectric constant at I kHz is 1000. 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 = {Ceramics, Electron microscopy, ferroelectricity, Oxides}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2005.04.003}, author = {Pasricha, R and Ravi, V} }