Rare-earth-transition-metal (RETM) ferrimagnets have received great attention for their small magnetic moments and fast dynamics in the development of next-generation spintronic devices. Here, we study spin Hall magnetoresistance (SMR) in the RETM ferrimagnet and heavy-metal bilayers of ${\mathrm{Co}}_{1\text{−}x}{\mathrm{Tb}}_x/\mathrm{Pt}$. Anomalous temperature dependence of the SMR is observed, where the SMR changes nonmonotonically and has a valley next to the magnetization compensation temperature. Additionally, we find that the SMR varies significantly for different chemical compositions of ${\mathrm{Co}}_{1\text{−}x}{\mathrm{Tb}}_x$ alloys. These anomalous behaviors are interpreted as the dramatically altered spin polarization of the ${\mathrm{Co}}_{1\text{−}x}{\mathrm{Tb}}_x$ layer near the compensation point. By deducing spin polarization from the abnormal temperature dependence of SMR, we provide a convenient way to access spin polarization of the RETM ferrimagnets. These experimental results show implications for tunable spin-current sources of RETM ferrimagnets.

中文翻译：

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自旋霍尔磁阻揭示铁磁Co1-xTbx / Pt双层中的自旋极化补偿

稀土过渡金属（RETM）铁氧体因其较小的磁矩和快速的动力学特性在下一代自旋电子器件的开发中受到了广泛的关注。在这里，我们研究RETM铁氧体和铁氧体的重金属双层中的自旋霍尔磁阻（SMR）${\mathrm{有限公司}}_{\mathrm{1个}\text{-}X}{b}_X/铂$。观察到SMR的温度依赖性异常，其中SMR非单调变化并且在磁化补偿温度旁边有一个谷值。此外，我们发现SMR对于不同的化学成分具有显着差异${\mathrm{有限公司}}_{\mathrm{1个}\text{-}X}{b}_X$合金。这些异常行为被解释为：${\mathrm{有限公司}}_{\mathrm{1个}\text{-}X}{b}_X$补偿点附近的层。通过从SMR的异常温度依赖性推论出自旋极化，我们提供了一种方便的方法来访问RETM Ferrimagnets的自旋极化。这些实验结果显示出RETM铁质可调自旋电流源的含义。