Spin Seebeck effect in thin films of the Heusler compound Co2MnSi
Spin Seebeck effect in thin films of the Heusler compound Co2MnSi
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DOI：
10.1103/physrevb.83.224401
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发表时间：
2011-06-16
影响因子：
3.7
通讯作者：
Takanashi, K.
中科院分区：
文献类型：
--
作者：
Bosu, S.;Sakuraba, Y.;Takanashi, K.
为了研究半金属Heusler化合物Co2MnSi(CMS)/Pt薄膜中的自旋Seebeck效应(SSE)，研究了铁磁层的自旋极化对SSE的影响。直接在MgO(001)衬底上制备了具有近乎完美的B2有序结构的CMS外延薄膜。测量是在室温下进行的，不同的温差，沿薄膜的较高(300K+Delta T)和较低(300K)温度端的Delta T=0-20K。利用铂丝中的反向自旋-霍尔效应，在CMS薄膜的高温和低温端检测到SSE引起的热致自旋电压明显反转。此外，我们还研究了沉积在MgO(001)衬底上的Py薄膜的SSE，并与CMS薄膜的SSE进行了比较，以验证自旋极化对SSE的影响。CMS和Py薄膜中SSE的相似信号表明，磁子的热激发可能比铁磁金属中的自旋极化程度对SSE有更重要的影响。
The recently discovered spin Seebeck effect (SSE) which generates spin voltage due to a temperature gradient in ferromagnets, was systematically studied in half-metallic Heusler compound Co2MnSi (CMS)/Pt thin films to investigate the effect of spin polarization of ferromagnetic layer on SSE. An epitaxial thin film of CMS with an almost perfect B2-ordered structure was prepared directly on a MgO(001) substrate. The measurement was performed at room temperature for various temperature differences, Delta T = 0-20 K between higher (300 K+Delta T) and lower (300 K) temperature ends along the film. The clear sign reversal of the thermally induced spin voltage due to SSE at the higher and lower temperature ends of the CMS film was detected by means of inverse spin-Hall effect in a Pt wire. The SSE was also investigated in a Py thin film deposited on a MgO(001) substrate and compared to that with CMS to verify the effect of spin polarization on SSE. Comparable signals of SSE in CMS and Py thin films suggested that thermal excitation of magnons might have more vital effects in SSE than the degree of spin polarization in ferromagnetic metals.