Dynamic interface formation in magnetic thin film heterostructures

TL;DR

This study investigates how the magnetic and electronic properties of Mn/Fe thin film heterostructures change dynamically with Mn coverage, revealing a two-step spin reorientation transition driven by interfacial alloy formation and electronic hybridization.

Contribution

It provides a detailed atomic-scale understanding of the interfacial factors influencing magnetic transitions in heterostructures, combining experimental techniques with first-principles calculations.

Findings

Two-step spin reorientation transition observed with increasing Mn coverage.

Low Mn coverage induces FeMn alloy formation at the interface.

High Mn coverage effects are dominated by electronic hybridization with ordered alloy.

Abstract

Magnetic thin film heterostructures have been widely studied for fundamental interests in the emergence of novel phenomena accompanied by the heterointerface formation as well as their promising practical potential. Combining x-ray magnetic circular dichroism with scanning tunneling microscopy, we show for Mn/Fe thin film heterostructures that the interfacial factors dominating electronic and magnetic properties of the entire system dynamically change with the amount of the Mn overlayer. Element specific magnetization curves of the Fe layer exhibit a two-step spin reorientation transition from out-of-plane to in-plane direction with increasing the Mn coverage. Atomic-scale characterizations of structural and electronic properties in combination with the first-principles calculations successfully unravel the roles of the entangled interfacial factors, and clarify the driving forces of the transition. The first step of the transition at a low Mn coverage is dominantly induced by the formation of FeMn disordered alloy at the heterointerface, and the electronic hybridization with interfacial FeMn ordered alloy is dominant as the origin of the second step of the transition at a high Mn coverage.