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arXiv · 1501.03962

Magnetic dichroism study on Mn$_{1.8}$Co$_{1.2}$Ga thin film using a combination of X-ray absorption and photoemission spectroscopy

Siham Ouardi·Gerhard H. Fecher·Takahide Kubota·Shigemi Mizukami·Eiji Ikenaga·Tetsuya Nakamura·Claudia Felser
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Abstract

Using circularly polarised radiation and a combination of bulk-sensitive hard X-ray photoelectron spectroscopy and X-ray-absorption spectroscopy (XAS) we studied the electronic and magnetic structure of epitaxial Mn$_{1.8}$Co$_{1.2}$Ga thin films. Spin resolved Bloch spectral functions, density of states as well as charge and magnetisation densities were investigated by a first-principles analysis of full potential, fully relativistic Korringa--Kohn--Rostoker calculations of the electronic structure. The valence states were experimentally investigated by using linear dichroism in the angular distribution and comparing the results to spin-resolved densities of states. The linear dichroism in the valence band enabled a symmetry analysis of the contributing states. The spectra were in good agreement with the theoretical partial density of states. The element-specific, spin-resolved, unoccupied densities of states for Co and Mn were analysed by using XAS and X-ray magnetic circular dichroism (XMCD) at the $L_{3,2}$ edges. The spectra were influenced by strong correlation effects. XMCD was used to extract the site resolved magnetic moments. The experimental values of $m_{\rm Mn}=0.7\:μ_B$ and $m_{\rm Co}=1.05\:μ_B$ agree very well with the calculated magnetic moments. Magnetic circular dichroism in angle-resolved photoelectron spectroscopy at the Mn and Co $2p$ core level exhibited a pronounced magnetic dichroism and confirmed the localised character of the Mn $d$ valence states.

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Siham Ouardi, Gerhard H. Fecher, Takahide Kubota, Shigemi Mizukami, Eiji Ikenaga, Tetsuya Nakamura, Claudia Felser. 2015-01-16. Magnetic dichroism study on Mn$_{1.8}$Co$_{1.2}$Ga thin film using a combination of X-ray absorption and photoemission spectroscopy. https://doi.org/10.1088/0022-3727%2F48%2F16%2F164007

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