Elucidate interfacial disorder effects on the perpendicular magnetic anisotropy at Fe/MgO heterostructure from first-principles calculations

Safdar Nazir; Kesong Yang

doi:10.1088/1361-648X/ac5a92

Elucidate interfacial disorder effects on the perpendicular magnetic anisotropy at Fe/MgO heterostructure from first-principles calculations

J Phys Condens Matter. 2022 Mar 23;34(21). doi: 10.1088/1361-648X/ac5a92.

Authors

Safdar Nazir¹, Kesong Yang^{1

2

3}

Affiliations

¹ Department of NanoEngineering and Program of Chemical Engineering, University of California San Diego, La Jolla, CA 92093-0448, United States of America.
² Program of Materials Science and Engineering, University of California San Diego, La Jolla, CA 92093-0418, United States of America.
³ Center for Memory and Recording Research, University of California San Diego, La Jolla, CA 92093-0401, United States of America.

PMID: 35240586
DOI: 10.1088/1361-648X/ac5a92

Abstract

The interfacial perpendicular magnetic anisotropy (PMA) plays a key role in spintronic applications such as memory recording and computational devices. Despite robust PMA being reported at the Fe/MgO interface, there are still inconsistencies in the disorder effects on the interfacial magnetic anisotropy. Here we reported a comprehensive study of the influence of the interfacial disorder, including the underoxidization, overoxidization, and oxygen migration, on the PMA of the Fe/MgO interface using first-principles calculations. Compared to the pristine Fe/MgO interface, the underoxidation at the Fe/MgO interface keeps the interfacial PMA but reduces the interfacial anisotropy constant (K_i). The overoxidization and oxygen migration at the interface both reduce theK_iand even switch the easy magnetization axis from the out-of-plane to in-plane direction at high oxygen percentage. In all the cases, theK_iwas found strongly correlated to the difference of the orbital magnetic moment along the in-plane and out-of-plane direction. Calculated layer-resolved and orbital-resolvedK_irevealed that the orbital coupling between thed_xyanddx2-y2states of the interfacial Fe layer plays a key role in determining the interfacial magnetic anisotropy. This work provides deep insights into the oxidation effects on the interfacial magnetic anisotropy of Fe/MgO system and a possible avenue to tune theK_ivia interfacial engineering.

Keywords: Fe/MgO; disorder; first-principles; heterostructure; interface; perpendicular magnetic anisotropy.