Lattice-matched magnetic tunnel junctions using a Heusler alloy Co2FeAl and a cation-disorder spinel Mg-Al-O barrier
Lattice-matched magnetic tunnel junctions using a Heusler alloy Co2FeAl and a cation-disorder spinel Mg-Al-O barrier
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DOI：
10.1063/1.4904716
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发表时间：
2014-12
影响因子：
4
通讯作者：
T. Scheike;H. Sukegawa;T. Furubayashi;Z. Wen;K. Inomata;T. Ohkubo;K. Hono;S. Mitani
中科院分区：
文献类型：
--
作者：
T. Scheike;H. Sukegawa;T. Furubayashi;Z. Wen;K. Inomata;T. Ohkubo;K. Hono;S. Mitani
采用溅射和等离子体氧化的方法制备了由Heusler合金B2-Co2 FeAl（CFA）电极和阳离子无序尖晶石（Mg-Al-O）阻挡层组成的晶格匹配的磁性隧道结（MTJ）。在不考虑晶格缺陷影响的情况下，CFA/MgAl-O/CoFe（001）MTJ在室温下的隧道磁电阻（TMR）为228%（5 K时为398%）。在CFA和Mg-Al-O之间插入一层厚度≤1.5 nm的CoFe层，室温下的TMR比进一步提高到280%（5 K时为453%），这反映了控制势垒-电极界面态而不是晶格匹配的重要性。
Perfectly lattice-matched magnetic tunnel junctions (MTJs) consisting of a Heusler alloy B2-Co2FeAl (CFA) electrode and a cation-disorder spinel (Mg-Al-O) barrier were fabricated by sputtering and plasma oxidation. We achieved a large tunnel magnetoresistance (TMR) ratio of 228% at room temperature (RT) (398% at 5 K) for the epitaxial CFA/MgAl-O/CoFe(001) MTJ, in which the effect of lattice defects on TMR ratios is excluded. With inserting a ultrathin (≤1.5 nm) CoFe layer between the CFA and Mg-Al-O, the TMR ratio further increased up to 280% at RT (453% at 5 K), which reflected the importance of controlling barrier-electrode interface states other than the lattice matching.