Spin-orbit torque-driven magnetization switching and thermal effects studied in Ta\CoFeB\MgO nanowires

TL;DR

This paper investigates spin-orbit torque-driven magnetization switching in Ta extbar CoFeB extbar MgO nanowires, highlighting thermal effects and modeling the process with a generalized Nel-Brown approach.

Contribution

It demonstrates magnetization switching driven by spin-orbit torques in nanowires and models thermal effects using a generalized Nel-Brown framework, providing key parameters of the switching process.

Findings

Switching driven by spin-orbit effects in multilayers.

Thermal fluctuations can induce switching without a longitudinal magnetic field.

Estimated parameters include attempt frequency and energy barrier.

Abstract

We demonstrate magnetization switching in out-of-plane magnetized Ta\CoFeB\MgO nanowires by current pulse injection along the nanowires, both with and without a constant and uniform magnetic field collinear to the current direction. We deduce that an effective torque arising from spin-orbit effects in the multilayer drives the switching mechanism. While the generation of a component of the magnetization along the current direction is crucial for the switching to occur, we observe that even without a longitudinal field thermally generated magnetization fluctuations can lead to switching. Analysis using a generalized N\'eel-Brown model enables key parameters of the thermally induced spin-orbit torques switching process to be estimated, such as the attempt frequency and the effective energy barrier.