Magnetic particle hyperthermia: Neel relaxation in magnetic nanoparticles under circularly polarized field

Abstract

The mechanism of magnetization reversal in single-domain ferromagnetic particles is of interest in many applications, in most of which losses must be minimized. In cancer therapy by hyperthermia the opposite requirement prevails: the specific loss power should be maximized. Of the mechanisms of dissipation, here we study the effect of Neel relaxation on magnetic nanoparticles unable to move or rotate and compare the losses in linearly and circularly polarized field. We present exact analytical solutions of the Landau-Lifshitz equation as derived from the Gilbert equation and use the calculated time-dependent magnetizations to find the energy loss per cycle. In frequencies lower than the Larmor frequency linear polarization is found to be the better source of heat power, at high frequencies (beyond the Larmor frequency) circular polarization is preferable.

arXiv comment9 pages, 2 figures, final version, published in J. Phys.: Condens. Matter

References in corpus (2)

• Dynamical and thermal effects in nanoparticle systems driven by a rotating magnetic field
• Ratchet Effect in Magnetization Reversal of Stoner Particles

Cited by in corpus (6)

• Magnetic particle hyperthermia: Power losses under circularly polarized field in anisotropic nanoparticles
• Uniform and Nonuniform Precession of a Nanoparticle with Finite Anisotropy in a Liquid: Opportunities and Limitations for Magnetic Fluid Hyperthermia
• Efficiency of magnetic hyperthermia in the presence of rotating and static fields
• Improved efficiency of heat generation in nonlinear dynamics of magnetic nanoparticles
• Theory of superlocalized magnetic nanoparticle hyperthermia: rotating versus oscillating fields
• Larmor precession and Debye relaxation of single-domain magnetic nanoparticles