@article { ISI:000284238000010, title = {Fabrication of homogeneous nanoparticle/nanoneedle BaTiO3 and Ba0.8Sr0.2TiO3 smooth thin films by simple dip coating}, journal = {International Journal of Nanotechnology}, volume = {7}, number = {9-12, SI}, year = {2010}, month = {DEC}, pages = {919-931}, publisher = {INDERSCIENCE ENTERPRISES LTD}, address = {WORLD TRADE CENTER BLDG, 29 ROUTE DE PRE-BOIS, CASE POSTALE 896, CH-1215 GENEVA, SWITZERLAND}, abstract = {

Ferroelectric BaTiO3 (BTO) and Ba0.8Sr0.2TiO3 (BSTO) thin film materials have been successfully prepared by sol-gel processing and simple dip coating on glass and silicon supports. Above thin films were characterised by x-ray diffraction (XRD), Raman spectroscopy, photoelectron spectroscopy, thermal analysis, atomic force microscopy (AFM) and spectroscopic ellipsometry. Phase identification of BaTiO3 and Ba0.8Sr0.2TiO3 was performed by XRD. XRD and Raman spectroscopy investigations demonstrate that thc Ba0.8Sr0.2TiO3 film exhibits tetragonal structure. AFM analysis demonstrates the elongated nanospherical particles on glass substrate and nanowires on silicon substrate, which represent a strong influence of the crystallinity of underlying substrate on the grain morphology in this technique. The thin films on both the substrates are uniformly coated without any pinhole to significant area (similar to 2.5 cm(2)), and this method might be extended to large area uniform coating. Spectroscopic ellipsometric measurements reveal the exact thickness, refractive index and extinction coefficient of the thin films.

}, keywords = {barium strontium titanate, barium titanate, dip coating, fabrication, ferroelectric material, large area coating, nanotechnology, thin film}, issn = {1475-7435}, author = {Saini, Mamta and Vivekanand, K. and Poddar, Pankaj and Murty, K. V. G. K. and Thushara, K. S. and Gopinath, Chinnakonda S.} } @article { ISI:000290015600029, title = {Field emission studies of silver nanoparticles synthesized by electron cyclotron resonance plasma}, journal = {Applied Surface Science}, volume = {257}, number = {16}, year = {2011}, month = {JUN}, pages = {7184-7189}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Field emission has been studied for silver nanoparticles (25-200 nm), deposited within a cylindrical silver target in an electron cyclotron resonance (ECR) plasma. Particle size distribution was controlled by optimum biasing voltages between the chamber and the target. Presence of non-oxidized silver was confirmed from the X-Ray diffraction analysis; however, thin protective layer of oxide was identified from the selective area electron diffraction pattern obtained with transmission electron microscopy. The silver nanoparticles were seen to exhibit hilly pointed like structures when viewed under the atomic force microscopy (AFM). The emissive properties of these particles were investigated by field emission microscopy. It is found that this technique of deposition is ideal for formation of nanoparticles films on different substrate geometries with size controllability as well as its application to emission devices. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {Cold plasma, field emission, Nanoparticles, thin film}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2011.03.088}, author = {Purohit, Vishwas and Mazumder, Baishakhi and Bhise, Ashok B. and Poddar, Pankaj and Joag, Dilip S. and Bhoraskar, S. V.} } @article { ISI:000346168600001, title = {Modification of crystal anisotropy and enhancement of magnetic moment of Co-doped SnO2 thin films annealed under magnetic field}, journal = {Nanoscale Research Letters}, volume = {9}, year = {2014}, month = {NOV}, pages = {635}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Co-doped SnO2 thin films were grown by sputtering technique on SiO2/Si(001) substrates at room temperature, and then, thermal treatments with and without an applied magnetic field (H-TT) were performed in vacuum at 600 degrees C for 20 min. H-TT was applied parallel and perpendicular to the substrate surface. Magnetic M(H) measurements reveal the coexistence of a strong antiferromagnetic (AFM) signal and a ferromagnetic (FM) component. The AFM component has a N,el temperature higher than room temperature, the spin axis lies parallel to the substrate surface, and the highest magnetic moment m =7 mu(B)/Co at. is obtained when H-TT is applied parallel to the substrate surface. Our results show an enhancement of FM moment per Co+2 from 0.06 to 0.42 mu(B)/Co at. for the sample on which H-TT was applied perpendicular to the surface. The FM order is attributed to the coupling of Co+2 ions through electrons trapped at the site of oxygen vacancies, as described by the bound magnetic polaron model. Our results suggest that FM order is aligned along [101] direction of Co-doped SnO2 nanocrystals, which is proposed to be the easy magnetization axis.

}, keywords = {Antiferromagnetism, Crystal anisotropy, Diluted magnetic oxide, Ferromagnetism, Magnetic anisotropy, Magnetic moment, Spin axis, thin film}, issn = {1556-276X}, doi = {10.1186/1556-276X-9-635}, author = {Loya-Mancilla, Sagrario M. and Poddar, Pankaj and Das, Raja and Ponce, Hilda E. Esparza and Templeton-Olivares, Ivan L. and Solis-Canto, Oscar O. and Ornelas-Gutierrez, Carlos E. and Espinosa-Magaa, Francisco and Olive-Mendez, Sion F.} }