Enhancement of Spin Pumping from CoFeB to Sb2Te3 Layers by Crystal Orientation Control
Enhancement of Spin Pumping from CoFeB to Sb2Te3 Layers by Crystal Orientation Control
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DOI：
10.1002/pssr.202100247
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发表时间：
2021-07
期刊：
影响因子：
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通讯作者：
M. Morota;Y. Saito;N. Uchida
中科院分区：
文献类型：
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作者：
M. Morota;Y. Saito;N. Uchida
Sb 2 Te 3作为相变材料是众所周知的，并且由于其强的自旋-轨道相互作用而被期望表现出高的自旋-电荷电流转换。可逆的相变特性使得能够根据相来操纵物理性质。因此，可以预见，它的自旋特性也可以通过控制Sb 2 Te 3的相来调节，有望成为新型自旋电子器件的巨大潜力。然而，结晶度对Sb 2 Te 3的自旋性质的影响尚未被研究。在此，自旋泵效应在CoFeB/Sb 2 Te 3双层膜中引起的自旋弛豫使用铁磁共振（FMR）在300 K下检查结晶和非晶Sb 2 Te 3。FMR信号宽度的增强观察高度取向的结晶Sb 2 Te 3膜在厚度小于7 nm。相反，非晶样品的FMR信号宽度与层厚度无关。线宽的显着增加表明更有效的自旋注入从铁磁CoFeB层到结晶Sb 2 Te 3比到非晶Sb 2 Te 3。非晶和结晶Sb 2 Te 3膜的自旋动力学之间的这种鲜明对比支持了可以通过控制Sb 2 Te 3膜的晶体取向来调谐自旋传导的想法。
Sb2Te3 is well known as a phase‐change material, and is expected to exhibit high spin–charge current conversion because of its strong spin–orbit interactions. Reversible phase‐change characteristics enable manipulation of physical properties depending on phase. Therefore, it is anticipated that its spin properties can also be tuned by controlling the phases of Sb2Te3, promising great potential for novel spintronic devices. However, the effects of crystallinity on the spin properties of Sb2Te3 have not yet been investigated. Herein, the spin relaxation induced by the spin‐pumping effect in CoFeB/Sb2Te3 bilayers is examined using ferromagnetic resonance (FMR) at 300 K for crystalline and amorphous Sb2Te3. FMR signal width enhancement is observed for the highly oriented crystalline Sb2Te3 film at thickness less than 7 nm. In contrast, the FMR signal widths of the amorphous sample are independent of the layer thickness. The significant increase in linewidth suggests more efficient spin injection from the ferromagnetic CoFeB layer into crystalline Sb2Te3 than into amorphous Sb2Te3. This stark contrast between the spin dynamics of the amorphous and crystalline Sb2Te3 films supports the idea that spin conduction can be tuned by controlling the crystal orientation of Sb2Te3 films.