Hindawi Publishing Corporation Journal of Nanomaterials Volume 2013, Article ID 952540, 22 pages http://dx.doi.org/10.1155/2013/952540 Review Article Magnetic Nanoparticles: A Subject for Both Fundamental Research and Applications S. Bedanta,1 A. Barman,2 W. Kleemann,3 O. Petracic,4 and T. Seki5 1 School of Physical Sciences, National Institute of Science Education and Research (NISER), IOP Campus, Bhubaneswar 751005, India 2 Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake City, Kolkata 700098, India 3 Department of Physics, University Duisburg-Essen, 47057 Duisburg, Germany 4 Julich¨ Centre for Neutron Science JCNS and Peter Grunberg¨ Institute PGI, JARA-FIT, Forschungszentrum Julich¨ GmbH, 52425 Julich,¨ Germany 5 Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan Correspondence should be addressed to S. Bedanta;
[email protected] Received 16 July 2013; Accepted 19 October 2013 Academic Editor: Gaurav Mago Copyright © 2013 S. Bedanta et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Single domain magnetic nanoparticles (MNPs) have been a vivid subject of intense research for the last fifty years. Preparation of magnetic nanoparticles and nanostructures has been achieved by both bottom-up and top-down approaches. Single domain MNPs show Neel-Brown-like´ relaxation. The Stoner-Wohlfarth model describes the angular dependence of the switching ofthe magnetization of a single domain particle in applied magnetic fields.