Influence of the thickness of the FeCoGd layer on the magnetoresistance in FeCoGd-based spin valves and magnetic tunnel junctions
Influence of the thickness of the FeCoGd layer on the magnetoresistance in FeCoGd-based spin valves and magnetic tunnel junctions
复制标题
FeCoGd 层厚度对 FeCoGd 基自旋阀和磁隧道结磁阻的影响
DOI：
10.1088/0022-3727/41/21/215008
复制
发表时间：
2008-11-07
影响因子：
3.4
通讯作者：
Zhou, S. M.
中科院分区：
文献类型：
--
作者：
Bai, X. J.;Du, J.;Zhou, S. M.
在FeCoGd（t）/Cu/FeCoGd的自旋阀（SV）和FeCoGd（t）/AlO/FeCo的磁性隧道结（MTJs）中观察到了不同FeCoGd层厚度（t）的正向和反向磁电阻效应。在室温下，对于SV中的巨磁电阻（GMR）比，当t = 17.2 nm时保持正值，当t = 18.4 nm时变为负值;对于MTJ中的隧道磁电阻比，当t = 15.4 nm时保持正值，当t = 16.5 nm时变为负值。在低温下，从5到300 K的SV中，我们发现，对于t = 17.2 nm，当T低于50 K时，GMR比保持为负，而当T高于75 K时，GMR比变为正。然而，对于t = 18.4 nm，GMR比在整个温度范围内始终为负。对FeCoGd层磁性的研究表明，上述结果是由于FeCoGd层中Gd和FeCo子网络间磁矩的竞争也随t和T的变化而变化。
Both normal and inverse magnetoresistance effects have been observed in spin valves (SVs) of FeCoGd(t)/Cu/FeCoGd and magnetic tunnel junctions (MTJs) of FeCoGd(t)/AlO/FeCo with different thicknesses (t) of the FeCoGd layer. At room temperature, for the giant magnetoresistance (GMR) ratio in the SVs, it remains positive when t ⩽ 17.2 nm and changes to negative when t ⩾ 18.4 nm; for the tunnelling magnetoresistance ratio in the MTJs, it remains positive when t ⩽ 15.4 nm and changes to negative when t ⩾ 16.5 nm. At low temperatures, ranging from 5 to 300 K in the SVs, we find that for t = 17.2 nm, the GMR ratio remains negative when T is lower than 50 K, while it becomes positive when T is higher than 75 K. However, for t = 18.4 nm, the GMR ratio is always negative in the whole temperature range. Studies on the magnetic property of the FeCoGd layer indicate that the above results are due to the competition of magnetic moments between Gd and FeCo subnetworks in the FeCoGd layer changes with t and T as well.