Testing epitaxial Co1.5Fe1.5Ge(001) electrodes in MgO-based magnetic tunnel junctions
Testing epitaxial Co1.5Fe1.5Ge(001) electrodes in MgO-based magnetic tunnel junctions
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测试 MgO 基磁性隧道结中的外延 Co1.5Fe1.5Ge(001) 电极
DOI：
10.1063/1.4885354
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发表时间：
2014
影响因子：
4
通讯作者：
S. Andrieu
中科院分区：
文献类型：
--
作者：
A. Neggache;T. Hauet;F. Bertran;P. Fèvre;S. Petit;T. Devolder;P. Ohresser;P. Boulet;C. Mewes;S. Maat;J. Childress;S. Andrieu
研究了全Heusler合金Co1.5Fe1.5Ge(001)(CFG)作为半金属磁性材料的能力。用分子束外延技术生长了CFG(001)外延层。用电子衍射、X射线衍射和X射线磁性圆二色谱得到的结果与完整的Heusler结构一致。用自旋分辨光电子能谱研究了隐马尔可夫模型中典型态的少数自旋密度中的赝隙。有趣的是，在等摩尔CoFe(001)中发现在EF处的自旋极化是负的，当在CoFe中加入Ge时，自旋极化向正值移动。然而，即使在HMM材料中观察到中等的磁化强度和低的Gilbert衰减，在费米水平上也没有发现伪能隙。用自旋分辨光电子能谱和对称分辨光电子能谱研究了使用CFG电极的氧化镁基磁隧道结的磁输运特性。
The ability of the full Heusler alloy Co1.5Fe1.5Ge(001) (CFG) to be a Half-Metallic Magnetic (HMM) material is investigated. Epitaxial CFG(001) layers were grown by molecular beam epitaxy. The results obtained using electron diffraction, X-ray diffraction, and X-ray magnetic circular dichroism are consistent with the full Heusler structure. The pseudo-gap in the minority spin density of state typical in HMM is examined using spin-resolved photoemission. Interestingly, the spin polarization found to be negative at EF in equimolar CoFe(001) is observed to shift to positive values when inserting Ge in CoFe. However, no pseudo-gap is found at the Fermi level, even if moderate magnetization and low Gilbert damping are observed as expected in HMM materials. Magneto-transport properties in MgO-based magnetic tunnel junctions using CFG electrodes are investigated via spin and symmetry resolved photoemission.