Entropy-reduced retention times in magnetic memory elements: A case of the Meyer-Neldel Compensation Rule

Abstract

We compute mean waiting times between thermally-activated magnetization reversals in a nanodisk with parameters similar to a free CoFeB layer used in magnetic random access memories. By combining Langer's theory and forward flux sampling simulations, we show that the Arrhenius prefactor can take values up to 10${}^{21}$ Hz, orders of magnitude beyond the value of 10${}^9$ Hz typically assumed, and varies drastically as a function of material parameters. We show that the prefactor behaves like an exponential of the activation energy, which highlights a case of the Meyer-Neldel compensation rule. This suggests that modeling information retention times with a barrier-independent prefactor in such magnetic storage elements is not justified.

5 pages, 4 figures

References in corpus (1)

• Calculating thermal stability and attempt frequency of advanced recording structures without free parameters

Cited by in corpus (2)

• Texture fluctuations and emergent dynamics in coupled nanomagnets
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