Thermally activated magnetization reversal in monatomic magnetic chains on surfaces studied by classical atomistic spin-dynamics simulations

Bauer, D.; Blügel, S.; Mavropoulos, Ph.; Lounis, S.

doi:10.1088/0953-8984/23/39/394204

Journal Article

Thermally activated magnetization reversal in monatomic magnetic chains on surfaces studied by classical atomistic spin-dynamics simulations

Bauer, D.FZJ* ; Mavropoulos, P.FZJ* ; Lounis, S.FZJ* ; Blügel, S.FZJ*

2011
IOP Publ. Bristol

Journal of physics / Condensed matter 23, 394204 (2011) [10.1088/0953-8984/23/39/394204]

This record in other databases:

Please use a persistent id in citations: http://hdl.handle.net/2128/23202 doi:10.1088/0953-8984/23/39/394204

Abstract: We analyse the spontaneous magnetization reversal of supported monatomic chains of finite length due to thermal fluctuations via atomistic spin-dynamics simulations. Our approach is based on the integration of the Landau-Lifshitz equation of motion of a classical spin Hamiltonian in the presence of stochastic forces. The associated magnetization lifetime is found to obey an Arrhenius law with an activation barrier equal to the domain wall energy in the chain. For chains longer than one domain wall width, the reversal is initiated by nucleation of a reversed magnetization domain primarily at the chain edge followed by a subsequent propagation of the domain wall to the other edge in a random-walk fashion. This results in a linear dependence of the lifetime on the chain length, if the magnetization correlation length is not exceeded. We studied chains of uniaxial and triaxial anisotropy and found that a triaxial anisotropy leads to a reduction of the magnetization lifetime due to a higher reversal attempt rate, even though the activation barrier is not changed.

Keyword(s): J

Classification:

Physics, Condensed Matter

Note: We are grateful to Dr Riccardo Hertel for discussions on the physics of magnetization dynamics, Dr Laszlo Szunyogh for discussions on the form of the anisotropy tensor in surface-supported chains, and Professor Christian Schroder for discussions on the methodology of atomistic spin dynamics. This work has been supported in part by FP7 EU-ITN FANTOMAS. SL wishes to thank the Alexander von Humboldt Foundation for a Feodor Lynen Fellowship and also Professor D L Mills for hospitality at the UC-Irvine.

Contributing Institute(s):

Research Program(s):