论文标题
在氧化物/铁磁金属界面处的垂直磁各向异性和dzyaloshinskii-moriya相互作用
Perpendicular magnetic anisotropy and Dzyaloshinskii-Moriya interaction at an oxide/ferromagnetic metal interface
论文作者
论文摘要
我们在氧化物/铁磁金属（FM）界面，即Batio3（BTO）/COFEB上报告了垂直磁各向异性（PMA）和Dzyaloshinskii-Moriya相互作用（DMI）的研究。由于BTO膜的功能性能以及精确控制其生长的能力，我们能够区分氧化物终止的主要作用（Tio2 vs Bao）与BTO膜在氧化物/FM界面上PMA和DMI上的铁电偏振的中等效应。我们发现，BAO-BTO/COFEB结构的界面磁各向异性能量比TiO2-BTO/COFEB大的两倍，而TiO2-BTO/COFEB界面的DMI较大。我们通过第一原理计算来解释观察到的现象，这些现象将它们归因于氧化物/铁磁金属界面和不同的自旋flip过程的费米水平附近的不同电子状态。这项研究为在各种氧化物/FM结构上进一步研究PMA和DMI铺平了道路，从而在有前途的节能设备领域中应用。
We report on the study of both perpendicular magnetic anisotropy (PMA) and Dzyaloshinskii-Moriya interaction (DMI) at an oxide/ferromagnetic metal (FM) interface, i.e. BaTiO3 (BTO)/CoFeB. Thanks to the functional properties of the BTO film and the capability to precisely control its growth, we are able to distinguish the dominant role of the oxide termination (TiO2 vs BaO), from the moderate effect of ferroelectric polarization in the BTO film, on the PMA and DMI at the oxide/FM interface. We find that the interfacial magnetic anisotropy energy of the BaO-BTO/CoFeB structure is two times larger than that of the TiO2-BTO/CoFeB, while the DMI of the TiO2-BTO/CoFeB interface is larger. We explain the observed phenomena by first-principles calculations, which ascribe them to the different electronic states around the Fermi level at the oxide/ferromagnetic metal interfaces and the different spin-flip processes. This study paves the way for further investigation of the PMA and DMI at various oxide/FM structures and thus their applications in the promising field of energy-efficient devices.
