Ionic control of magnetic properties, dubbed magneto-ionics, has gained much attention in recent years due to the sizable effects that can be induced by electrically-controlled ion motion. Here we assess the mechanism by which hydrogen affects magnetic anisotropy in representative ferro- magnetic/heavy metal layers, namely Co/Pd films, widely used in spintronics. First-principles calculations demonstrate that the magnetic moment can be switched by 90 via hydrogen insertion at the Co/Pd interface. This control results from hydrogen-induced changes in magnetic anisotropy originating from modifications to the electronic structure. Accumulation of hydrogen at the Co/Pd interface affects the hybridization between neighboring Co and Pd layers, leading to a decrease of the perpendicular anisotropy component, and eventually changes the net magnetic anisotropy to in-plane. Hydrogen penetration into the interior Co layers has the opposite effect, promoting perpendicular magnetic anisotropy. These changes are governed by competing contributions of the dxy ; dx2 +y2 and the 3dz2 ; 3dzy states, which are mainly responsible for the perpendicular and the in-plane magneto-crystalline anisotropy, respectively. By using this understanding, we predict that hydrogen accumulation at Fe/V interfacial layers causes the opposite spin reorientation effect, promoting perpendicular magnetic anisotropy.

中文翻译：

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氢通过影响铁磁体与非磁性金属界面处的局部杂化来调节磁各向异性

近年来，由于电控离子运动可引起巨大的影响，因此人们对磁性的离子控制（称为磁离子）进行了广泛关注。在这里，我们评估了氢影响自旋电子学中广泛使用的代表性铁磁/重金属层（即Co / Pd膜）中的磁各向异性的机理。第一性原理计算表明，可以通过在Co / Pd界面处插入氢将磁矩切换90度。这种控制是由于氢引起的磁各向异性的变化而引起的，该磁各向异性的变化源于对电子结构的修改。氢在Co / Pd界面处的积累会影响相邻的Co和Pd层之间的杂化，从而导致垂直各向异性成分的减少，最终将净磁各向异性改变为面内 氢渗透到内部Co层中的作用相反，从而促进了垂直磁各向异性。这些变化由dxy的竞争贡献决定; dx2 + y2和3dz2; 3dzy态，分别负责垂直和面内磁晶各向异性。通过这种理解，我们预测氢在Fe / V界面层的积累会引起相反的自旋重取向效应，从而促进垂直磁各向异性。主要负责垂直和面内磁晶各向异性。通过这种理解，我们预测氢在Fe / V界面层的积累会引起相反的自旋重取向效应，从而促进垂直磁各向异性。主要负责垂直和面内磁晶各向异性。通过这种理解，我们预测氢在Fe / V界面层的积累会引起相反的自旋重取向效应，从而促进垂直磁各向异性。