학술논문

Tuning the Magnetic Anisotropy of NiPtMnGa by Substitution and Epitaxial Strain
Document Type
Periodical
Source
IEEE Transactions on Magnetics IEEE Trans. Magn. Magnetics, IEEE Transactions on. 55(2):1-4 Feb, 2019
Subject
Fields, Waves and Electromagnetics
Manganese
Perpendicular magnetic anisotropy
Nickel
Strain
Anisotropic magnetoresistance
Lattices
Ab+initio<%2Fitalic>+investigations%22">Ab initio investigations
Heusler alloys
magnetic properties
magnetocrystalline anisotropy (MCA)
thin films
Language
ISSN
0018-9464
1941-0069
Abstract
Large magnetocrystalline anisotropy (MCA) is of high technical relevance, in particular for magnetic actuators, permanent magnets, and memory devices with high density. Large MCAs have been reported for the low temperature L1 0 phase of Ni 2 MnGa. Both, Mn and Pt substitution can stabilize this phase at and above room temperature. Despite the larger spin–orbit coupling in the heavy $5d$ -element Pt, it has been reported that Pt substitution may result in degeneration of the MCA. In this paper, we study the MCA for a combination of epitaxial strain and Mn and Pt substitution based on density functional theory methods. We show that one can stabilize both large uniaxial and easy-plane anisotropies depending on the value of strain. In particular, small changes of the applied strain may allow to switch between low- and high-anisotropy states or even switch the direction of the easy-axis magnetization direction.