[18p-E216-1~10] 10.4 Semiconductor spintronics, superconductor, multiferroics

▼ [18p-E216-2] Influence of the interface quality on the estimation of the spin-to-charge conversion efficiency in spin pumping experiments on Co₂FeAl_0.5Si_0.5/n-Ge

〇(M1)Shingo Kaneta¹, Shoma Arai¹, Anh Le Duc^1,2, Michihiro Yamada⁴, Kohei Hamaya^4,5, Shinobu Ohya^1,2,3 (1.Univ. of Tokyo, 2.IEI, Univ. of Tokyo, 3.CSRN, Univ. of Tokyo, 4.Osaka Univ., 5.CSRN, Osaka Univ.)

Keywords:Semiconductor spintronics, Spin pumping, Spin-to-charge conversion

Spin pumping is believed to be a very efficient way to inject a spin current from a ferromagnet (FM) to a non-magnet (NM). However, the influence of the FM/NM interface quality, which is thought to affect the spin injection efficiency, has not been discussed. In this work, we investigate the influence of the Co2FeAl0.5Si0.5(CFAS)/n-Ge interface quality on the estimation of the spin-to-charge conversion efficiency by spin pumping. We grew CFAS/n-Ge on a Si(111) substrate via molecular beam epitaxy. We have prepared the as-grown sample and the one annealed to interdiffuse atoms at the CFAS/n-Ge interface. For these samples, we have carried out spin pumping. The electromotive force is different between the as-grown and annealed samples. From these results, spin Hall angle is estimated to be 0.0015 for the as-grown and 0.0077 for the annealed at 300 K. In our presentation, we discuss the correlation between the estimated value of spin Hall angle and the interface quality in more detail.