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arXiv · 1211.2440

Perpendicularly magnetized Mn-Co-Ga-based thin films with high coercive field

Siham Ouardi·Takahide Kubota·Gerhard H. Fecher·Rolf Stinshoff·Shigemi Mizukami·Terunobu Miyazaki·Eiji Ikenaga·Claudia Felser
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Abstract

Mn$_{3-x}$Co$_{x}$Ga epitaxial thin films were grown on MgO substrates by magnetron co-sputtering. Structures were tetragonal or cubic depending on Co content. Composition dependence of saturation magnetization and uniaxial magnetic anisotropy $K_u$ of the films were investigated. A high $K_u$ (1.2 MJ m$^{-3}$) was achieved for the Mn$_{2.6}$Co$_{0.3}$Ga$_{1.1}$ film with the magnetic moment 0.84$μ_B$. Valence band spectra were obtained by hard X-ray photoelectron spectroscopy. Sharp peaks in the cubic case, which were absent in the tetragonal case, prove that a van Hove singularity causes a band Jahn-Teller effect with tetragonal distortion. Observations agree well with the first-principles calculations.

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Siham Ouardi, Takahide Kubota, Gerhard H. Fecher, Rolf Stinshoff, Shigemi Mizukami, Terunobu Miyazaki, Eiji Ikenaga, Claudia Felser. 2012-11-11. Perpendicularly magnetized Mn-Co-Ga-based thin films with high coercive field. https://doi.org/10.1063/1.4770303

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