Thermoelectric effects and magnetic anisotropy of Ga 1-x Mn x As thin films
Thermoelectric effects and magnetic anisotropy of Ga 1-x Mn x As thin films
复制标题
Ga 1-x Mn x As薄膜的热电效应和磁各向异性
DOI：
10.1103/physrevb.90.104423
复制
发表时间：
2014
影响因子：
3.7
通讯作者：
R. Schäfer
中科院分区：
文献类型：
--
作者：
I. V. Soldatov;N. Panarina;C. Hess;L. Schultz;R. Schäfer
本文系统地分析了平面霍尔效应和横向自旋塞贝克效应两种结构下铁磁半导体中产生的横向电压。所观察到的场依赖性包括对称和非对称的贡献。前者归因于在存在面内温度梯度的情况下磁性膜中的平面能斯特效应，而后者是由由于系数高达500的假面外温度梯度引起的反常能斯特效应引起的。我们还报告了在不同温度下测量的平面霍尔效应的实验观察。利用Stoner-Wohlfarth模型进行数据分析，确定了磁膜中叠加的单轴和立方各向异性的各向异性常数和。随着温度的升高，在低温下占主导地位的立方各向异性逐渐被单轴各向异性所取代。同时使用克尔显微镜观察畴结构，证实了这种行为，在不同的温度下，表现出不同的领域的演变。
The transverse voltages generated in aferromagnetic semiconductor in planar Hall effect and transverse spin Seebeck effect configurations are systematically analyzed. The observed field dependences consist of symmetric and asymmetric contributions. The former is attributed to the planar Nernst effect in the magnetic film in the presence of an in-plane temperature gradient, while the latter is caused by the anomalous Nernst effect due to spurious out-of-plane temperature gradients with a coefficient as high as 500. We also report on the experimental observation of the planar Hall effect measured at different temperatures. Using a Stoner-Wohlfarth model for data analysis, the anisotropy constantsandof superimposed uniaxial and cubic anisotropies in the magnetic film are determined. The temperature dependence of theratio reveals a gradual substitution of the cubic anisotropy dominating at low temperatures with the uniaxial anisotropy as the temperature rises. This behavior is confirmed by the simultaneous domain observation using Kerr microscopy, demonstrating different field evolutions of the domain structure at different temperatures.