@article { ISI:000288772300011, title = {Magnetic properties of thermal plasma synthesized nanocrystalline nickel ferrite (NiFe2O4)}, journal = {Journal of Alloys and Compounds}, volume = {509}, number = {12}, year = {2011}, month = {MAR}, pages = {4404-4413}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

A rapid synthesis method is reported for magnetic nanoparticles of nickel ferrite involving thermal plasma assisted vapor phase condensation process. The as-synthesized samples were characterized by X-ray Diffraction, Transmission Electron Microscopy, Vibrating Sample Magnetometer and X-ray Photoelectron Spectroscopy techniques. The average particle size was determined from the TEM micrographs and found to be around 30 nm. The effects of reactor parameters on the magnetic and structural properties have been evaluated, to find the optimized parameters so as to achieve the highest values of saturation magnetization and coercivity. Reasonably high saturation magnetization (48 emu/g) has been assigned to the high degree of crystallinity, achieved on account of high temperature during the growth, and the cation redistribution. The high value of coercivity (1150e) is explained on the basis of possible lattice defects arising from the cation redistribution. Detailed analysis of cation distribution using the XRD line intensity data leads to the conclusion that these samples are iron deficit and nickel rich. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {crystal structure, Magnetic measurements, Magnetization, Nanostructured materials, TEM}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2011.01.057}, author = {Nawale, Ashok B. and Kanhe, Nilesh S. and Patil, K. R. and Bhoraskar, S. V. and Mathe, Vikas L. and Das, A. K.} } @article { ISI:000313404400021, title = {Magnetic properties of nanocrystalline CoFe2O4 synthesized by thermal plasma in large scale}, journal = {Materials Chemistry and Physics}, volume = {137}, number = {2}, year = {2012}, month = {DEC}, pages = {586-595}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

The paper reports the large scale synthesis of nanoparticles of CoFe2O4 using thermal plasma reactor by gas phase condensation method. The yield of formation was found to be around 15 g h(-1). The magnetic properties of CoFe2O4, synthesized at different reactor powers, were investigated in view of studying the effect of operating parameters of plasma reactor on the structural reorganization leading to the different cation distribution. The values of saturation magnetization, coercivity and remanent magnetization were found to be influenced by input power in thermal plasma. Although the increase in saturation magnetization was marginal (61 emu g(-1) to 70 emu g(-1)) with increasing plasma power; a significant increase in the coercivity (552 Oe to 849 Oe) and remanent magnetization (16 emu g(-1) to 26 emu g(-1)) were also noticed. The Mossbauer spectra showed mixed spinel structure and canted spin order for the as synthesized nanoparticles. The detailed analysis of cation distribution using the Mossbauer spectroscopy and X-ray photoelectron spectroscopy leads to the conclusion that the sample synthesized at an optimized power shows the different site selective states. (C) 2012 Elsevier B.V. All rights reserved.

}, keywords = {Magnetic materials, magnetic properties, Mossbauer spectroscopy, Nanostructures}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2012.10.007}, author = {Nawale, A. B. and Kanhe, Nilesh S. and Patil, K. R. and Reddy, V. R. and Gupta, A. and Kale, B. B. and Bhoraskar, S. V. and Mathe, Vikas L. and Das, A. K.} } @article { ISI:000361312700001, title = {Micro-structural analysis of NiFe2O4 nanoparticles synthesized by thermal plasma route and its suitability for BSA adsorption}, journal = {Journal of Materials Science-Materials in Medicine}, volume = {26}, number = {8}, year = {2015}, month = {AUG}, pages = {216}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

The paper presents the experimental studies pertaining to the adsorption of bovine serum albumin (BSA) on the nanoparticles of nickel ferrite (NiFe2O4) with a view of correlating the adsorption properties to their microstructure and zeta potentials. Physical properties of two kinds of nickel ferrites, one synthesized by thermal plasma route and the other by chemical co-precipitation method, are compared. Maximum adsorption (231.57 lg/mg) of BSA onto nickel ferrite nanoparticles, at body temperature (37 degrees C) was observed at pH-value of 5.58 for the thermal plasma synthesized particles showing its higher adsorption capacity than those synthesized by wet chemical means (178.71 mu g/mg). Under the same physical conditions the value of zeta potential, obtained for the former, was higher than that of the latter over a wide range of pH values (3.64-9.66). This is attributed to the differences in the specific surface energies of the two kinds of nanoparticles arising from the degree of crystallinity. The paper presents the experimental evidence for the single crystalline nature of the individual nanoparticles, with mean size of 32 nm, for the thermal plasma synthesized particles as evidenced from the high resolution transmission electron microscopy and electron diffraction analysis. The measurements also reveal the poor crystalline morphology in the chemically prepared particles (mean size of 28 nm) although the X-ray diffraction patterns are not much different. The atomic force microscopy images confirm that the surfaces of plasma synthesized nanoparticles possesses higher surface roughness than that of chemically synthesized one. Presence of adsorbed protein was confirmed by vibrational spectroscopy. The Langmuir adsorption model is found to fit into the experimental data better than the Freundlich adsorption model.

}, issn = {0957-4530}, doi = {10.1007/s10856-015-5547-7}, author = {Bhosale, Shivaji V. and Kanhe, Nilesh S. and Bhoraskar, S. V. and Bhat, Suresh K. and Bulakhe, Ravindra N. and Shim, Jae-Jin and Mathe, Vikas L.} }