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arXiv · 1702.00996

Significant reduction of critical currents in MRAM designs using dual free layer with perpendicular and in-plane anisotropy

Dieter Suess·Christoph Vogler·Florian Bruckner·Hossein Sepehri-Amin·Claas Abert
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Abstract

One essential feature in MRAM cells is the spin torque efficiency, which describes the ratio of the critical switching current to the energy barrier. Within this paper it is reported that the spin torque efficiency can be improved by a factor of 3.2 by the use a of dual free layer device, which consists of one layer with perpendicular crystalline anisotropy and a second layer with in-plane crystalline anisotropy. Detailed simulations solving the spin transport equations simultaneously with the micromagnetics equation were performed in order to understand the origin of the switching current reduction by a factor of 4 for the dual layer structure compared to a single layer structure. The main reason could be attributed to an increased spin accumulation within the free layer due to the dynamical tilting of the magnetization within the in-plane region of the dual free layer.

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Dieter Suess, Christoph Vogler, Florian Bruckner, Hossein Sepehri-Amin, Claas Abert. 2017-02-03. Significant reduction of critical currents in MRAM designs using dual free layer with perpendicular and in-plane anisotropy. https://doi.org/10.1063/1.4987140

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