The Fe/MgO interface is an essential ingredient in spintronics as it shows giant tunneling magnetoresistance and strong perpendicular magnetic anisotropy (PMA). A recent study demonstrated that the insertion of an ultra-thin LiF layer between the Fe and MgO layers enhances PMA significantly. In this study, we perform x-ray magnetic circular dichroism measurements on Fe/LiF/MgO multilayers to reveal the origin of the PMA enhancement. We find that the LiF insertion increases the orbital-magnetic-moment anisotropy and thus the magnetic anisotropy energy. We attribute the origin of this orbital-magnetic-moment-anisotropy enhancement to the stronger electron localization and electron-electron correlation or the better interface quality with fewer defects.
@article{arxiv.2208.07007,
title = {The origin of enhanced interfacial perpendicular magnetic anisotropy in LiF-inserted Fe/MgO interface},
author = {Shoya Sakamoto and Takayuki Nozaki and Shinji Yuasa and Kenta Amemiya and Shinji Miwa},
journal= {arXiv preprint arXiv:2208.07007},
year = {2022}
}