Strong correlation between uniaxial magnetic anisotropic constant and in-plane tensile strain in Mn4N epitaxial films

• TOKO, Kaoru

• SUEMASU, Takashi

• Hirose, Taku

• Komori, Taro

• Gushi, Toshiki

• Anzai, Akihito

Abstract

Ferrimagnetic Mn4N is a promising candidate for current-induced domain wall motion assisted by spin-transfer and spin–orbit torques. Mn4N can be doped to have perpendicular magnetic anisotropy (PMA) and a small spontaneous magnetization. However, the origin of the PMA of Mn4N has yet to be fully understood. Here, we investigated the relationship between the ratios of the perpendicular lattice constant c to the in-plane lattice constant a of Mn4N epitaxial thin films (c/a) and the uniaxial magnetic anisotropic constant (Ku) in Mn4N thin films grown on MgO(001), SrTiO3(001), and LaAlO3(001) substrates. The lattice mismatches between Mn4N and these substrates are approximately −6%, −0.1%, and +2%, respectively. All the Mn4N thin films had PMA and in-plane tensile distortion (c/a < 1) regardless of the Mn4N thickness and substrate. Although the magnitude of c/a depended on several factors, such as the Mn4N layer thickness and substrate, we found a strong correlation between c/a and Ku; Ku increased markedly when c/a deviated from 1. This result indicates that the origin of PMA is tensile distortion in Mn4N films; hence, it might be possible to control the magnitude of Ku by tuning c/a through the Mn4N layer thickness and the substrate.

Journal

• AIP Advances

  AIP Advances 10 (2), 025117-, 2020-01

  American Institute of Physics

Keywords

• General Physics and Astronomy

Details

• CRID: 1050848249881355264
• NII Article ID: 120007127659
• DOI: 10.1063/1.5141818
• ISSN: 21583226
• HANDLE: 2241/00160219
• Web Site: https://tsukuba.repo.nii.ac.jp/records/54811
• Web Site: https://pubs.aip.org/aip/adv/article-pdf/doi/10.1063/1.5141818/12882151/025117_1_online.pdf
• Text Lang: en
• Article Type: journal article
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