@article { ISI:000239975900022, title = {In situ optical emission spectroscopic investigations during arc plasma synthesis of iron oxide nanoparticles by thermal plasma}, journal = {IEEE Transactions on Plasma Science}, volume = {34}, number = {4, 1}, year = {2006}, month = {AUG}, pages = {1175-1182}, publisher = {IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC}, type = {Article}, address = {445 HOES LANE, PISCATAWAY, NJ 08855 USA}, abstract = {

Investigations using in situ precursor spectroscopy during the growth of nanoparticles of iron oxide by thermal plasma induced gas phase condensation method have been shown to be useful for correlating the size of nanoparticles with existing plasma parameters. The relative abundance of ionized Fe species inside the plasma plume is seen to directly establish the relation between particle size, arc current, arc length, and ambient pressure of the reacting oxygen gas. The argon plasma from a transferred arc reactor is made to impinge on the anode that is allowed to vaporize and react with oxygen. The spectral line profiles of both Ar and Fe along the plasma column during the synthesis of nanoparticles have been proved to be useful in understanding the growth mechanism. Band intensities of FeO molecular states indicated the inverse relation with particle sizes that have been correlated to the two competitive processes in which energy is released, namely: 1) one involving the radiative transition and 2) the other that of the growth by coagulation. Atomic Boltzmann plots are used for estimating the temperatures of the zones, whereas particle sizes have been inferred using transmission electron microscopic measurements.

}, keywords = {plasma arc device, plasma-materials processing applications, spectroscopy}, issn = {0093-3813}, doi = {10.1109/TPS.2006.878430}, author = {Banerjee, Indrani and Joshi, N. K. and Sahasrabudhe, S. N. and Kulkarni, Naveen V. and Karmakar, Soumen and Pasricha, R. and Ghorui, S. and Tak, Atul K. and Murthy, Shri P. S. S. and Bhoraskar, S. V. and Das, A. K.} } @article { ISI:000235256200004, title = {Preparation of gamma-Fe2O3 nanoparticles using DC thermal arc-plasma route, their characterization and magnetic properties}, journal = {Scripta Materialia}, volume = {54}, number = {7}, year = {2006}, month = {APR}, pages = {1235-1240}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

gamma-Fe2O3 particles were prepared, for the first time, using a direct current thermal arc-plasma route. The powder was characterized using X-ray diffraction, Mossbauer spectroscopy, X-ray photoelectron spectroscopy, chemical analysis, vibrating sample magnetometry C and transmission electron microscopy. The high purity, stoichiometry and spherical morphology of the gamma-Fe2O3 particles (saturation magnetization = 79 emu g(-1) and coercivity = 348 Oe) were confirmed. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

}, keywords = {chemical analysis, DC thermal arc-plasma route, maghemite, Mossbauer spectroscopy, XPS}, issn = {1359-6462}, doi = {10.1016/j.scriptamat.2005.12.029}, author = {Banerjee, Indrani and Khollam, Y. B. and Balasubramanian, C. and Pasricha, R. and Bakare, P. P. and Patil, K. R. and Das, A. K. and Bhoraskar, S. V.} } @article { ISI:000258965100011, title = {Mossbauer spectroscopic investigations of nanophase iron oxides synthesized by thermal plasma route}, journal = {Materials Characterization}, volume = {59}, number = {9}, year = {2008}, month = {SEP}, pages = {1215-1220}, publisher = {ELSEVIER SCIENCE INC}, address = {360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA}, abstract = {

Magnetic nanoparticles of iron oxide were synthesized by transferred arc plasma induced gas phase condensation method. Structural, morphological and magnetic studies of the as synthesized powder were carried out using X-ray diffraction, transmission electron microscopy and Mossbauer spectroscopy. These studies have revealed the simultaneous nucleation and condensation of different magnetic phases with a broad size distribution of the nanoparticles which is peaked at 30-50 nm and ranges from 10 nm to 80 nm. 57 Fe Mossbauer spectra recorded at various temperatures (5 K-300 K) in presence of external magnetic field (at 5 K) have suggested the presence of different phases of iron oxide with sizable amounts of gamma-Fe2O3 and alpha-Fe2O3 in addition to Fe3O4. The relative concentrations of these phases have been obtained by a self consistent spectral area analysis and were found to be 44:22:34 (\%). (C) 2007 Elsevier Inc. All rights reserved.

}, keywords = {iron oxides, Mossbauer spectroscopy, phase analysis, plasma synthesis}, issn = {1044-5803}, doi = {10.1016/j.matchar.2007.10.003}, author = {Nagar, Harshada and Kulkarni, Naveen V. and Karmakar, Soumen and Sahoo, B. and Banerjee, Indrani and Chaudhari, P. S. and Pasricha, R. and Das, A. K. and Bhoraskar, S. V. and Date, Sadgopal K. and Keune, W.} } @article { ISI:000286305100010, title = {Effect of leakage current and dielectric constant on single and double layer oxides in MOS structure}, journal = {Thin Solid Films}, volume = {519}, number = {5, SI}, year = {2010}, note = {37th International Conference on Metallurgical Coatings and Thin Films, San Diego, CA, APR 26-30, 2010}, month = {DEC}, pages = {1530-1535}, publisher = {Amer Vacuum Soc, Adv Surface Engn Div}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

MOS structure of Al/Al2O3/n-Si, Al/TiO2/n-Si and Al/Al2O3/TiO2/n-Si was obtained by deposition of Al2O3 and TiO2 on silicon substrate by RF Magnetron Sputtering system. The total thickness of the oxide layer similar to 40 +/- 5 nm in the MOS structure was kept constant. Samples were characterized by X-Ray diffraction (XRD). X-Ray photoelectron spectroscopy (XPS), Impedance analyzer and Current-voltage (J-V) characteristics. The variations in the dielectric constant and tan 8 of the MOS capacitor in the frequency range of 1000Hz-1MHz were measured by impedance analyzer. The variation in dielectric constant of the Al/Al2O3/TiO2/n-Si multilayer compared to single layer of Al/Al2O3/n-Si and Al/TiO2/n-Si is due to high probability of defects, lattice mismatch and interface interactions. The steep rise of Tan 6 values in the Al/Al2O3/TiO2/n-Si structure is due to the resonance effect of both Al2O3 and TiO2 layers. The leakage current mechanisms of MOS structures were extracted from Schottky coefficient and Poole-Frenkel coefficient. Theoretical values of Schottky coefficients (beta(SC)) and Poole-Frenkel coefficients (beta(PF)) for each sample were estimated using the real part of the dielectric constant. The experimental values were calculated from J-V characteristics and compared with theoretical values. The appropriate model has been proposed. It was found that Schottky and Poole-Frenkel mechanisms are applicable at low and high field respectively for all MOS structures. The combination of Al/Al2O3/TiO2/n-Si is found to be a promising structure with high dielectric constant and low leakage current suitable for MOS devices. (C) 2010 Elsevier B.V. All rights reserved.

}, keywords = {Al2O3, dielectric constant, Leakage current, MOS device, Poole-Frenkel emission, Schottky emission, TiO2}, issn = {0040-6090}, doi = {10.1016/j.tsf.2010.08.089}, author = {Laha, Pinaki and Panda, A. B. and Dahiwale, S. and Date, Kalyani S. and Patil, K. R. and Barhai, P. K. and Das, A. K. and Banerjee, Indrani and Mahapatra, S. K.} } @article { ISI:000283745300023, title = {Study of the effect of plasma-striking atmosphere on Fe-oxidation in thermal dc arc-plasma processing}, journal = {Journal of Vacuum Science \& Technology A}, volume = {28}, number = {6}, year = {2010}, month = {NOV}, pages = {1399-1403}, publisher = {A V S AMER INST PHYSICS}, address = {STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA}, abstract = {

The effect of plasma-striking atmosphere: air and air+Ar-gas on the crystallization of Fe-oxide phases was studied using dc thermal arc-plasma processing route. The powders were characterized by x-ray diffraction, vibrating sample magnetometry, transmission electron microscopy, and Mossbauer spectroscopy techniques. At room temperature and O(2) rich atmosphere, arc-evaporated Fe(2+) ions oxidize into either gamma-Fe(2)O(3) or Fe(3)O(4) depending upon the combining ratio of Fe with molecular O(2). Fe/O ratio could be adjusted using proper flow rate of Ar gas to crystallize the pure gamma-Fe(2)O(3). (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3504597]

}, issn = {0734-2101}, doi = {10.1116/1.3504597}, author = {Banerjee, Indrani and Khollam, Y. B. and Mahapatra, S. K. and Das, A. K. and Bhoraskar, S. V.} }