Composition-tuned magneto-optical Kerr effect in L10-MnxGa films with giant perpendicular anisotropy

TL;DR

This study demonstrates giant polar magneto-optical Kerr effect in L10-MnxGa films with high perpendicular anisotropy, tunable Kerr rotation, and potential for spintronics and terahertz applications.

Contribution

It reveals composition-dependent enhancement of Kerr effect and magnetic anisotropy in L10-MnxGa films, expanding their application potential.

Findings

Kerr rotation up to 0.10 degrees

High reflectivity of 35%-55% in 400-850 nm

Giant magnetic anisotropic field up to 210 kOe

Abstract

We report the large polar magnetooptical Kerr effect in L10-MnxGa epitaxial films with giant perpendicular magnetic anisotropy in a wide composition range. The Kerr rotation was enhanced by a factor of up to 10 by decreasing Mn atomic concentration, which most likely arises from the variation of the effective spin-orbit coupling strength, compensation effect of magnetic moments at different Mn atom sites, and overall strain. The Kerr ellipticity and the magnitude of the complex Kerr angle is found to have more complex composition-dependence that varies with the photon energy. These L10-MnxGa films show large Kerr rotation of up to 0.10o, high reflectivity of 35%-55% in a wide wavelength range of 400~850 nm, and giant magnetic anisotropic field of up to 210 kOe, making them an interesting material system for emerging spintronics and terahertz modulator applications.