Anisotropic Magnetoresistance Effects in Fe, Co, Ni, Fe4N, and Half-Metallic Ferromagnet: A Systematic Analysis
Anisotropic Magnetoresistance Effects in Fe, Co, Ni, Fe4N, and Half-Metallic Ferromagnet: A Systematic Analysis
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DOI：
10.1143/jpsj.81.024705
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发表时间：
2012-02-01
影响因子：
1.7
通讯作者：
Sakuma, Akimasa
中科院分区：
文献类型：
--
作者：
Kokado, Satoshi;Tsunoda, Masakiyo;Sakuma, Akimasa
本文从理论上分析了bcc结构Fe（+）、fcc结构Co（+）、fcc结构Ni（+）、Fe 4 N（-）和半金属铁磁体（-）的各向异性磁电阻效应。每个括号中的符号表示实验观察到的AMR比率的符号。在这里，我们使用的两个电流模型的系统组成的自旋极化的导电状态和本地化的d态与自旋轨道相互作用。从该模型中，我们首先推导出AMR比率的一般表达式。该表达式由sigma自旋的导电状态的电阻率（sigma =向上箭头或向下箭头）、ρ（s sigma）和由于从导电状态到局域d状态的s-d散射过程引起的双折射率组成。在此表达式的基础上，我们接下来找到AMR比的符号与s-d散射过程之间的关系。此外，我们得到的AMR比的表达式适合于各自的材料。使用表达式，我们评估它们的AMR比率，其中表达式考虑了相应材料的rho（s向下箭头）/rho（s向上箭头）的值。所评估的AMR比率与实验结果吻合良好。
We theoretically analyze the anisotropic magnetoresistance (AMR) effects of bcc Fe (+), fcc Co (+), fcc Ni (+), Fe4N (-), and a half-metallic ferromagnet (-). The sign in each parenthesis represents the sign of the AMR ratio observed experimentally. We here use the two-current model for a system consisting of a spin-polarized conduction state and localized d states with spin-orbit interaction. From the model, we first derive a general expression of the AMR ratio. The expression consists of a resistivity of the conduction state of the sigma spin (sigma = up arrow or down arrow), rho(s sigma), and resistivities due to s-d scattering processes from the conduction state to the localized d states. On the basis of this expression, we next find a relation between the sign of the AMR ratio and the s-d scattering process. In addition, we obtain expressions of the AMR ratios appropriate to the respective materials. Using the expressions, we evaluate their AMR ratios, where the expressions take into account the values of rho(s down arrow)/rho(s up arrow) of the respective materials. The evaluated AMR ratios correspond well to the experimental results.