Enhancement of perpendicular magnetic anisotropy and its electric field-induced change through interface engineering in Cr/Fe/MgO

TL;DR

This paper investigates how interface engineering, specifically Cr doping, enhances perpendicular magnetic anisotropy and its voltage control in Cr/Fe/MgO structures, revealing significant improvements in magnetic properties and VCMA effects.

Contribution

It demonstrates that controlled Cr doping at the Fe/MgO interface significantly enhances PMA and VCMA, providing insights into the origin of voltage-induced anisotropy changes.

Findings

Enhanced PMA with Cr doping at the interface.

Achieved maximum VCMA of 370 fJ/Vm.

Identified Cr atoms' role in magnetic anisotropy modulation.

Abstract

Recently, perpendicular magnetic anisotropy (PMA) and its voltage control (VC) was demonstrated for Cr/Fe/MgO (Physical Review Applied 5, 044006 (2016)). In this study, we shed a light on the origin of large voltage-induced anisotropy change in Cr/Fe/MgO. Analysis of the chemical structure of Cr/Fe/MgO revealed the existence of Cr atoms in the proximity of the Fe/MgO interface, which can affect both magnetic anisotropy (MA) and its VC. We showed that PMA and its VC can be enhanced by controlled Cr doping at the Fe/MgO interface. For Cr/Fe (5.9 {\AA})/Cr (0.7 {\AA})/MgO with an effective PMA of 0.8 MJ/m3, a maximum value of the voltage-controlled magnetic anisotropy (VCMA) effect of 370 fJ/Vm was demonstrated.