Relaxation and Hyperthermia Investigation on Magnetic Nanoparticle suspensions

POSTER

Abstract

We have examined the N\'{e}el and Brownian relaxation mechanisms and hyperthermia characteristics of aqueous suspension of $\gamma $- Fe$_2$O$_3$ and Fe$_3$O$_4$:Co$_{x}$ ( 0 $\le $ x $\le $ 0.15) nanoparticles by ac and dc magnetization measurements and specific absorption ratio (SAR) values. The structural properties were investigated by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). The ac susceptibility measurement showed dissipation peaks associated with N\'{e}el relaxation in $\gamma $- Fe$_2$O$_{3}$ and Fe$_3$O$_4$ samples but only the Fe$_3$O$_{4}$ sample showed a significant Brownian relaxation peak near the melting temperature of the carrier fluid. The specific absorption rate (SAR) value for the Fe$_{3}$O$_{4}$ sample is five times larger than that of the $\gamma $- Fe$_{2}$O$_{3}$ sample, which we attribute to reduced steric hindrance to rotation. Changes in the structural, magnetocrystalline, and SAR values on incorporating Co ions in Fe$_{3}$O$_{4}$ will be presented.

Authors

  • V. Bubulac

    Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201

  • P.P. Vaishnava

    Kettering Univ., Flint, MI 48504, Kettering University, Flint, MI 48504

  • R. Tackett

    Wayne State University, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201

  • C. Sudakar

    Wayne State University, Wayne State University, MI 48201, Wayne State Univ, Detroit, MI 48201, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201

  • R. Naik

    Wayne State University, Wayne State University, MI 48201, Wayne State Univ, Detroit, MI 48201, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201

  • G. Lawes

    Wayne State University, MI 48201, Wayne State University, Wayne State Univ, Detroit, MI 48201, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201