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arXiv · 2302.13387

Emergence of net magnetization by magnetic-field-biased diffusion in antiferromagnetic L1$_0$ NiMn

Nicolas Josten·Olga Miroshkina·Sakia Noorzayee·Benjamin Zingsem·Aslı Çakır·Mehmet Acet·Ulf Wiedwald·Markus Gruner·Michael Farle
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Abstract

NiMn is a collinear antiferromagnet with high magneto crystalline anisotropy ($K_2=-9.7\times10^5\;\text{J m}^{-3}$). Through magnetic annealing of NiMn with excess Ni, strongly pinned magnetic moments emerge due to an imbalance in the distribution of Ni in the antiferromagnetic Mn-sublattices. The results are explained with a model of magnetic-field-biased diffusion, supported by ab initio calculations. Another observation is the oxidation of Mn at the surface, causing an enrichment of Ni in the sub-surface region. This leads to an additional ferromagnetic response appearing in the magnetization measurements, which can be removed by surface polishing.

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Nicolas Josten, Olga Miroshkina, Sakia Noorzayee, Benjamin Zingsem, Aslı Çakır, Mehmet Acet, Ulf Wiedwald, Markus Gruner, Michael Farle. 2023-02-26. Emergence of net magnetization by magnetic-field-biased diffusion in antiferromagnetic L1$_0$ NiMn. https://doi.org/10.1103/physrevb.107.174417

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