3D MOKE spin-orbit torque magnetometer

TL;DR

This paper introduces a 3D MOKE magnetometer capable of simultaneously measuring all three magnetization components to accurately detect and analyze spin-orbit torques in heavy metal/ferromagnetic bilayers.

Contribution

It presents a novel 3D vector magneto-optic Kerr effect technique with self-calibration for precise spin-orbit torque measurement, improving upon existing methods.

Findings

Accurate measurement of spin-orbit torques in platinum/permalloy bilayers.

Values agree with other established measurement techniques.

Enhanced understanding of torque magnitude and direction.

Abstract

We demonstrate simultaneous detection of current driven antidamping-like and field-like spin-orbit torques in heavy metal/ferromagnetic metal bilayers by measuring all three magnetization components m_(x,) m_y, and m_z using the vector magneto-optic Kerr effect. We have also implemented a self-calibration method to accurately determine the effective fields of spin-orbit torques. With this technique, we investigate the magnitude and direction of spin-orbit torques in a series of platinum/permalloy samples. The values found are in excellent agreement with results obtained via quadratic magneto-optic Kerr effect, planar Hall effect, and spin transfer ferromagnetic resonance measurements.