Spin polarization of Co2FeSi full-Heusler alloy and tunneling magnetoresistance of its magnetic tunneling junctions
Spin polarization of Co2FeSi full-Heusler alloy and tunneling magnetoresistance of its magnetic tunneling junctions
复制标题
DOI：
10.1063/1.2338025
复制
发表时间：
2006-08-21
影响因子：
4
通讯作者：
Inomata, K.
中科院分区：
文献类型：
--
作者：
Gercsi, Z.;Rajanikanth, A.;Inomata, K.
作者报告了 MgO (001) 衬底上外延生长的 Co2FeSi 薄膜的自旋极化 (P) 和隧道磁阻 (TMR)。在 473 K 或以上溅射沉积的样品中观察到 Heusler 型 L2(1) 结构。通过点接触安德烈夫反射（PCAR）技术测量有序薄膜的P值为0.49+/-0.02。使用 Co2FeSi 电极和 Al 氧化物势垒从磁隧道结 (MTJ) 获得的 TMR 值分别在 5 K 时为 67.5%，在 298 K 时为 43.6%。使用 Julliere 模型从 TMR 估计的 P 值与 PCAR 测量的自旋极化非常匹配，表明 MTJ 的 TMR 值受非相干隧道效应电极材料的 P 的固有值控制。
The authors report spin polarization (P) and tunneling magnetoresistance (TMR) of epitaxially grown Co2FeSi thin films on a MgO (001) substrate. A Heusler-type L2(1) structure was observed in the samples sputter deposited at 473 K or above. The P value of the ordered film was measured as 0.49 +/- 0.02 by the point contact Andreev reflection (PCAR) technique. The TMR values obtained from the magnetic tunneling junction (MTJ) using the Co2FeSi electrode and Al-oxide barrier were 67.5% at 5 K and 43.6% at 298 K, respectively. The P value estimated from the TMR using Julliere's model matches the spin polarization measured by the PCAR very well, indicating that the TMR value from the MTJ is governed by the intrinsic value of P of the electrode material for incoherent tunneling.