Abstract
Abstract
MgO-based magnetic heterostructures with interfacial magnetic anisotropy has attracted increasing attention due to its application in building high-density magnetic random access memories. A large and tunable interfacial magnetic anisotropy constant (Ki) is required for high thermal stability and flexible data writability. In this study, the Ki of Fe/MgO, Fe/Pt/MgO, and Fe/Ir/MgO heterostructures with strains from −4.5% to 4.5% were calculated by ab initio electronic structure calculations. It has been found that the Fe/Pt/MgO and Fe/Ir/MgO where the Pt and Ir monolayers are inserted in the interface possess Ki of 2.415 mJ m−2 and −4.468 mJ m−2, which are much larger by several times than that (0.840 mJ m−2) of the Fe/MgO. In particular, the out-of-plane Ki from the interfacial Pt atoms in Fe/Pt/MgO is as high as 5.978 mJ m−2. The magnetic anisotropy of these structures can be significantly manipulated by strain. Combining second-order perturbation theory, the origin of these behaviors has been analyzed by layer-resolved, orbital-resolved, and k-resolved Ki. The spin-flip terms of d
z
2/d
yz
orbitals in the interfacial layer are mainly responsible for the out-of-plane Ki and its variation with strain. This work provides a useful guide for the design of high and tunable magnetic anisotropy in the MgO-based magnetic heterostructures.
Funder
School Scientific Research Project of Hangzhou Dianzi University
the Open Project of the National Laboratory of Solid State Microstructures, Nanjing University
the National Natural Science Foundation of China
Subject
Condensed Matter Physics,Mathematical Physics,Atomic and Molecular Physics, and Optics