Real-time MOKE microscopy made simple

TL;DR

This paper introduces a simple, real-time MOKE microscopy system for imaging magnetic domain dynamics in thin films, providing deeper insights into magnetization reversal processes and anisotropic behaviors.

Contribution

It presents a straightforward instrument that enhances magnetic imaging and interpretation of reversal processes beyond traditional hysteresis measurements.

Findings

Imaging reveals double-step reversal not seen in hysteresis loops.

System detects anisotropic domain dynamics near the hard axis.

Provides insights into unexplained hard axis coercivity behavior.

Abstract

We present a simple and effective instrument for simultaneous real-time imaging and hysteresis of the anisotropic magnetic domain dynamics in thin films using the Magneto-Optical Kerr Effect (MOKE). We furthermore illustrate that magnetic imaging allows a more accurate interpretation of the magnetization reversal processes than the conventional hysteresis characterization. In particular, we present a case where the onset of a double-step reversal observed in imaging remains invisible in the spatially integrated hysteresis loops. When complemented by precise tuning of the external magnetic field orientation, our system reveals the singular anisotropic variations of the domain dynamics near the hard-axis in epitaxial thin films, thus shedding light on the reported, but as yet unexplained, hard axis coercivity behavior.