Spin transport in as-grown and annealed thulium iron garnet/platinum bilayers with perpendicular magnetic anisotropy
Spin transport in as-grown and annealed thulium iron garnet/platinum bilayers with perpendicular magnetic anisotropy
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DOI：
10.1103/physrevb.95.115428
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发表时间：
2017-03
影响因子：
3.7
通讯作者：
C. Avci;A. Quindeau;M. Mann;C. Pai;C. Ross;G. Beach
中科院分区：
文献类型：
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作者：
C. Avci;A. Quindeau;M. Mann;C. Pai;C. Ross;G. Beach
利用谐波霍尔效应测量了具有垂直磁各向异性的铥铁石榴石/铂双层膜的自旋霍尔磁电阻（SMR）、自旋塞贝克效应（SSE）和类阻尼自旋轨道矩（SOT）.通过连续的退火步骤，然后对单个器件进行测量，我们发现随着退火温度的升高，自旋相关效应的幅度逐渐减小。我们将这种行为主要归因于自旋混合电导的变化，这敏感地取决于界面质量。然而，进一步的分析表明，尽管SSE与SMR密切相关，但阻尼类SOT在退火时显示出明显不同的趋势，与理论预期相反。通过比较类阻尼SOT与场致霍尔效应，我们发现证据表明，在界面处的Pt中的Fe杂质的散射可能是导致类阻尼SOT的明显退火温度依赖性的原因。
We characterize the spin Hall magnetoresistance (SMR), spin Seebeck effect (SSE), and dampinglike spin-orbit torque (SOT) in thulium iron garnet/platinum bilayers with perpendicular magnetic anisotropy by using harmonic Hall effect measurements. By consecutive annealing steps followed by measurements on a single device, we reveal that the spin-dependent effects gradually decrease in amplitude as the annealing temperature increases. We attribute this behavior primarily to the changes in the spin-mixing conductance, which sensitively depends on the interface quality. However, further analysis demonstrates that although the SSE scales closely with the SMR, the dampinglike SOT shows a significantly different trend upon annealing, contrary to theoretical expectations. By comparing the dampinglike SOT with the field-induced Hall effect, we found evidence that scattering from Fe impurities in the Pt at the interface might be responsible for the distinct annealing temperature dependence of the dampinglike SOT.