Mn-based alloys exhibit unique properties in the spintronics materials possessing perpendicular magnetic anisotropy (PMA) beyond the Fe and Co-based alloys. It is desired to figure out the quantum physics of PMA inherent to Mn-based alloys, which have never been reported. Here, the origin of PMA in ferrimagnetic Mn3−δGa ordered alloys is investigated to resolve antiparallel-coupled Mn sites using x-ray magnetic circular and linear dichroism (XMCD/XMLD) and a first-principles calculation. We found that the contribution of orbital magnetic moments in PMA is small from XMCD and that the finite quadrupole-like orbital distortion through spin-flipped electron hopping is dominant from XMLD and theoretical calculations. These findings suggest that the spin-flipped orbital quadrupole formations originate from the PMA in Mn3−δGa and bring the paradigm shift in the researches of PMA materials using x-ray magnetic spectroscopies.
@article{arxiv.2005.03249,
title = {Detecting quadrupole: a hidden source of magnetic anisotropy for Manganese alloys},
author = {Jun Okabayashi and Yoshio Miura and Yohei Kota and Kazuya Suzuki and Akimasa Sakuma and Shigemi Mizukami},
journal= {arXiv preprint arXiv:2005.03249},
year = {2020}
}