High Tunnel Magnetoresistance at Room Temperature in Fully Epitaxial Fe/MgO/Fe Tunnel Junctions due to Coherent Spin-Polarized Tunneling
High Tunnel Magnetoresistance at Room Temperature in Fully Epitaxial Fe/MgO/Fe Tunnel Junctions due to Coherent Spin-Polarized Tunneling
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DOI：
10.1143/jjap.43.l588
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发表时间：
2004-04
影响因子：
1.5
通讯作者：
S. Yuasa;A. Fukushima;T. Nagahama;K. Ando;Yoshishige Suzuki
中科院分区：
文献类型：
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作者：
S. Yuasa;A. Fukushima;T. Nagahama;K. Ando;Yoshishige Suzuki
我们制备了完全外延的Fe（001）/MgO（001）/Fe（001）磁性隧道结（MTJ），在T = 293 K时观察到88%的磁阻（MR）比（T = 20 K时为146%），这是迄今为止报道的最高值。高MR比的起源不是Julliere模型的扩散隧穿，而是外延MTJ中的相干自旋极化隧穿，其中只有相对于势垒法线轴具有完全对称波函数的电子才能隧穿。MR的偏置电压依赖性非常小，导致380 mV的高输出电压。这种高电压将有助于克服高密度磁阻随机存取存储器（MRAM）开发中的问题。
We fabricated fully epitaxial Fe(001)/MgO(001)/Fe(001) magnetic tunnel junctions (MTJs) and observed a magneto-resistance (MR) ratio of 88% at T = 293 K (146% at T = 20 K), the highest value yet reported. The origin of the high MR ratio is not the diffusive tunneling of Julliere's model but the coherent spin-polarized tunneling in epitaxial MTJs, in which only the electrons with totally symmetric wave functions with respect to the barrier-normal axis can tunnel. The bias-voltage dependence of the MR was very small, resulting in a high output voltage of 380 mV. This high voltage will help overcome problems in the development of high-density magnetoresistive random-access-memory (MRAM).