Effect of oxygen vacancies on spin-dependent tunneling in Fe/MgO/Fe
Effect of oxygen vacancies on spin-dependent tunneling in Fe/MgO/Fe
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DOI：
10.1063/1.2643027
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发表时间：
2007-02
期刊：
影响因子：
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通讯作者：
J. Velev;K. Belashchenko;S. Jaswal;E. Tsymbal
中科院分区：
文献类型：
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作者：
J. Velev;K. Belashchenko;S. Jaswal;E. Tsymbal
采用基于密度泛函理论的第一性原理计算方法，研究了O空位形成F中心对Fe scinMgO scinFe（001）磁性隧道结中自旋相关隧穿的影响. O空位产生占据的局域s态和未占据的共振p态，这与现有的实验数据是一致的。作者发现，O空位通过隧穿电子的非共振散射影响电导，导致隧穿磁电阻（TMR）的显著降低。提高MgO阻挡层的质量以降低O空位浓度将提高这些结和类似结中的TMR。
First-principles calculations based on density functional theory are used to elucidate the effect of O vacancies, forming F centers, on spin-dependent tunneling in Fe∕MgO∕Fe(001) magnetic tunnel junctions. O vacancies produce occupied localized s states and unoccupied resonant p states, which is consistent with available experimental data. The authors find that O vacancies affect the conductance by nonresonant scattering of tunneling electrons causing a substantial reduction of tunneling magnetoresistance (TMR). Improving the quality of the MgO barrier to reduce O vacancy concentration would improve TMR in these and similar junctions.