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arXiv · 0705.4454

Two Modes of Magnetization Switching in a Simulated Iron Nanopillar in an Obliquely Oriented Field

S. H. Thompson·G. Brown·P. A. Rikvold·M. A. Novotny
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Abstract

Finite-temperature micromagnetics simulations are employed to study the magnetization-switching dynamics driven by a field applied at an angle to the long axis of an iron nanopillar. A bi-modal distribution in the switching times is observed, and evidence for two competing modes of magnetization-switching dynamics is presented. For the conditions studied here, temperature $T = 20$ K and the reversal field 3160 Oe at an angle of 75$^\circ$ to the long axis, approximately 70% of the switches involve unstable decay (no free-energy barrier) and 30% involve metastable decay (a free-energy barrier is crossed). The latter are indistinguishable from switches which are constrained to start at a metastable free-energy minimum. Competition between unstable and metastable decay could greatly complicate applications involving magnetization switches near the coercive field.

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S. H. Thompson, G. Brown, P. A. Rikvold, M. A. Novotny. 2007-05-30. Two Modes of Magnetization Switching in a Simulated Iron Nanopillar in an Obliquely Oriented Field. https://doi.org/10.1088/0953-8984%2F22%2F23%2F236001

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