title: Magnetic particle hyperthermia: Néel 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 Néel relaxation on magnetic nanoparticles unable to move or rotate and compare the losses in linearly and circularly polarized fields. 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.
authors.affiliation: Institute of Nuclear Research, PO Box 51, H-4001 Debrecen, Hungary. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China.
authors.forename: P F
authors.initials: PF
authors.lastname: de Châtel
authors.forename: I
authors.initials: I
authors.lastname: Nándori
authors.forename: J
authors.initials: J
authors.lastname: Hakl
authors.forename: S
authors.initials: S
authors.lastname: Mészáros
authors.forename: K
authors.initials: K
authors.lastname: Vad