Instant-On Spin Torque in Noncollinear Magnetic Tunnel Junctions

© 2018 American Physical Society. Through recent advances, the relevance of magnetic tunnel junctions (MTJs) to the microelectronics industry continues to rise. However, their reversal speed still suffers from incubation delay, a consequence of the collinear magnetization equilibrium states in perpendicularly magnetized MTJs (p-MTJs). We propose to tune the free layer in a Co-Fe-B/MgO/Co-Fe-B stack close to the reorientation transition, aiming to inducing a noncollinearity between the free layer and the reference layer to improve the magnetization reversal speed. Upon varying the layer thickness, the introduction of an in-plane magnetic component is observed in the free layer. Through time-resolved step-response measurements of the conductance, the dynamics are observed to consist of a stochastic delay followed by a repeatable magnetization-reversal pathway. We explore the separation of the measured response into these components and find the power requirements and switching speed to improve over the p-MTJ reference. This is a direct demonstration of the noncollinear improvement pathway, which is appealing for applications where the switching speed and a low energy cost of operation prevail over long-term stability.

Jaar van publicatie:2018

BOF-keylabel:ja

IOF-keylabel:ja

BOF-publication weight:2

CSS-citation score:1

Auteurs:International

Authors from:Government, Higher Education

Toegankelijkheid:Closed