Magnetization reversal time of magnetic nanoparticles at very low damping

William T. Coffey (1) , Yuri P. Kalmykov (2) , Serguey V. Titov (3)

1 Department of Electronic and Electrical Engineering
2 LAMPS - LAboratoire de Modélisation Pluridisciplinaire et Simulations
3 IRE - Kotelnikov Institute of Radio Engineering and Electronics

The magnetization reversal time of magnetic nanoparticles is investigated in the very low damping regime. The energy-controlled diffusion equation, rooted in a generalization of the Kramers escape rate theory for point Brownian particles in a potential to the magnetic relaxation of a macrospin, yields the reversal time in closed integral form. The latter is calculated for a nanomagnet with uniaxial anisotropy with a uniform field applied at an angle to the easy axis and for a nanomagnet with biaxial anisotropy with the field along the easy axis. The results completely agree with those yielded by independent numerical and asymptotic methods.

Domaines: Physique [physics]

William T. Coffey, Yuri P. Kalmykov, Serguey V. Titov. Magnetization reversal time of magnetic nanoparticles at very low damping. Biophysical Reviews and Letters, 2014, 89 (5), http://link.aps.org/doi/10.1103/PhysRevB.89.054408. ⟨10.1103/PhysRevB.89.054408⟩. ⟨hal-01143085⟩