Employing soft x-ray magnetic circular dichroism (XMCD) and soft x-ray absorption spectroscopy (XAS), we have investigated electronic structures and spin configurations of Co-substituted ${\mathrm{Mn}}_3\mathrm{Ga}$ (${\mathrm{Mn}}_{3-x}{\mathrm{Co}}_x\mathrm{Ga}$) Heusler films, which are promising spintronic materials exhibiting perpendicular magnetic anisotropy (PMA). Co $2p$ XAS and XMCD measurements, combined with the charge-transfer multiplet analysis, show that the substituted Co ions in ${\mathrm{Mn}}_{3-x}{\mathrm{Co}}_x\mathrm{Ga}$ consist of mainly ferromagnetic metallic Co clusters and a small amount of divalent Co ions with disordered magnetic moments. Mn $2p$ XAS and XMCD measurements show that Mn ions at both the octahedral and tetrahedral sites in ${\mathrm{Mn}}_{3-x}{\mathrm{Co}}_x\mathrm{Ga}$ are nearly divalent with weak covalent-bonding nature, reflecting non-Jahn-Teller ions, and that the magnetic moments of Mn ions are polarized along the ordered magnetic moments of the substituted Co ions. Angle-dependent Co $2p$ XMCD data of ${\mathrm{Mn}}_{3-x}{\mathrm{Co}}_x\mathrm{Ga}$ agree with the weak magnetic anisotropy transition from PMA to in-plane magnetic anisotropy (IMA) with increasing $x$. Spin and orbital magnetic moments of Co ions are estimated by using the sum-rule analysis, which reveal negligible Co-content and polar-angle dependencies of the Co orbital to spin magnetic moment ratio. This work reveals that the PMA-to-IMA magnetic transition in ${\mathrm{Mn}}_{3-x}{\mathrm{Co}}_x\mathrm{Ga}$ is determined mainly by ferromagnetic metallic Co clusters.

中文翻译：

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软 X 射线光谱研究 Mn3−xCoxGaHeusler 薄膜的电子结构和磁各向异性跃迁

采用软 X 射线磁圆二色性 (XMCD) 和软 X 射线吸收光谱 (XAS)，我们研究了共取代的电子结构和自旋构型${锰}_3镓$(${锰}_{3-X}{\mathrm{公司}}_X镓$) Heusler 薄膜，这是一种很有前途的自旋电子材料，具有垂直磁各向异性 (PMA)。公司$2p$XAS 和 XMCD 测量，结合电荷转移多重分析，表明取代的 Co 离子在${锰}_{3-X}{\mathrm{公司}}_X镓$主要由铁磁性金属钴簇和少量具有无序磁矩的二价钴离子组成。锰$2p$XAS 和 XMCD 测量表明，Mn 离子在八面体和四面体位点${锰}_{3-X}{\mathrm{公司}}_X镓$几乎是二价的，具有弱共价键合性质，反映了非 Jahn-Teller 离子，并且 Mn 离子的磁矩沿着取代的 Co 离子的有序磁矩极化。角度相关系数$2p$XMCD数据${锰}_{3-X}{\mathrm{公司}}_X镓$同意从 PMA 到面内磁各向异性 (IMA) 的弱磁各向异性转变$X$. Co 离子的自旋和轨道磁矩是通过使用总和规则分析来估计的，这揭示了 Co 轨道与自旋磁矩比的可忽略的 Co 含量和极角依赖性。这项工作揭示了 PMA 到 IMA 的磁跃迁${锰}_{3-X}{\mathrm{公司}}_X镓$主要由铁磁性金属钴簇决定。