Table of Contents
Journal of Nanoparticles
Volume 2013 (2013), Article ID 181820, 13 pages
http://dx.doi.org/10.1155/2013/181820
Research Article

Magnetization and Specific Absorption Rate Studies of Ball-Milled Iron Oxide Nanoparticles for Biomedicine

1Department of Physics, Villanova University, Villanova, PA 19085, USA
2Department of Biology, Villanova University, Villanova, PA 19085, USA
3Department of Mechanical Engineering, Villanova University, Villanova, PA 19085, USA

Received 24 June 2013; Accepted 29 July 2013

Academic Editor: John Zhanhu Guo

Copyright © 2013 P. Burnham 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.

Abstract

Comparative studies are presented of iron oxide nanoparticles in the 7–15 nm average diameter range ball milled in hexane in the presence of oleic acid. Transmission electron microscopy identified spherical particles of decreasing size as milling time and/or surfactant concentration increased. Micromagnetic characterization via Mössbauer spectroscopy at room temperature yielded broadened magnetic spectroscopic signatures, while macromagnetic characterization via vibrating sample magnetometry of 7-8 nm diameter particles showed largely superparamagnetic behavior at room temperature and hysteretic at 2 K. Zero-field and field-cooled magnetization curves exhibited a broad maximum at ~215 K indicating the presence of strong interparticle magnetic interactions. The specific absorption rates of ferrofluids based on these nanoparticle preparations were measured in order to test their efficacies as hyperthermia agents.