@article { ISI:000264092400030, title = {Impact of zinc substitution on the structural and magnetic properties of chemically derived nanosized manganese zinc mixed ferrites}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {321}, number = {8}, year = {2009}, month = {APR}, pages = {1092-1099}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Mn(1-x)Zn(x)Fe(2)O(4) nanoparticles (x = 0-1) were synthesized by wet chemical co-precipitation techniques. X-ray diffraction, transmission electron microscopy and high-resolution transmission electron microscopy were effectively utilized to investigate the different structural parameters. The elemental analysis was conducted using energy-dispersive spectrum and inductively coupled plasma analysis. The magnetic properties such as magnetization and coercivity were measured using vibrating sample magnetometer. The observed magnetization values of the nanoparticles were found to be lower compared to the bulk counterpart. The magnetization showed a gradual decrease with zinc substitution except for a small increase from x = 0.2 to 0.3. The Curie temperature was found to be enhanced in the case of ferrites in the nanoregime. The variation in lattice constant, reduced magnetization values, variation of magnetization with zinc substitution, the presence of a net magnetic moment for the zinc ferrite and the enhancement in Curie temperature in Mn(1-x)Zn(x)Fe(2)O(4) all provide evidence to the existence of a metastable cation distribution together with possible surface effects at the nanoregime. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Manganese zinc ferrite}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2008.10.031}, author = {Gopalan, E. Veena and Al-Omari, I. A. and Malini, K. A. and Joy, Pattayil Alias and Kumar, D. Sakthi and Yoshida, Yasuhiko and Anantharaman, Maliemadom R.} } @article { ISI:000277784300022, title = {Inverse magnetocaloric effect in sol-gel derived nanosized cobalt ferrite}, journal = {Applied Physics A-Materials Science \& Processing}, volume = {99}, number = {2, SI}, year = {2010}, month = {MAY}, pages = {497-503}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

The magnetocaloric properties of cobalt ferrite nanoparticles were investigated to evaluate the potential of these materials as magnetic refrigerants. Nanosized cobalt ferrites were synthesized by the method of sol-gel combustion. The nanoparticles were found to be spherical with an average crystallite size of 14 nm. The magnetic entropy change (Delta S (m)) calculated indirectly from magnetization isotherms in the temperature region 170-320 K was found to be negative, signifying an inverse magnetocaloric effect in the nanoparticles. The magnitudes of the Delta S (m) values were found to be larger when compared to the reported values in the literature for the corresponding ferrite materials in the nanoregime.

}, issn = {0947-8396}, doi = {10.1007/s00339-010-5573-8}, author = {Gopalan, E. Veena and Al-Omari, I. A. and Kumar, D. Sakthi and Yoshida, Yasuhiko and Joy, Pattayil Alias and Anantharaman, Maliemadom R.} } @article { ISI:000324311200017, title = {Influence of initial particle size on the magnetostriction of sintered cobalt ferrite derived from nanocrystalline powders}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {346}, year = {2013}, month = {NOV}, pages = {96-102}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The role of initial particle size on the magnetostriction coefficient of sintered cobalt ferrite derived from nanocrystalline powders is studied. Nanoparticles of cobalt ferrite with different sizes in the range 3-80 nm are synthesized by an autocombustion method using metal nitrates and glycine. It has been observed that the initial particle size of the starting powders has a strong influence on the magnetostrictive behavior of sintered cobalt ferrite. Highest magnetostrictive strain and strain derivative are obtained for sintered ferrite derived from nanoparticles of size \< 5 nm. The results show that higher magnetostriction coefficient for sintered cobalt ferrite can be achieved by compacting nanocrystalline particles of very small size. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Cobalt ferrite, magnetic properties, Magnetostriction, Microstructure, Nanocrystalline, Particle size}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2013.07.016}, author = {Mohaideen, Kamal Khaja and Joy, Pattayil Alias} }