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arXiv · 2007.02152

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

L. Desplat·J. -V. Kim
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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.

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L. Desplat, J. -V. Kim. 2020-07-04. Entropy-reduced retention times in magnetic memory elements: A case of the Meyer-Neldel Compensation Rule. https://doi.org/10.1103/physrevlett.125.107201

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