[20p-E216-8~20] 10.2 Fundamental and exploratory device technologies for spin

▼ [20p-E216-18] Large spin signals of local 3-terminal spin valve effect in n-Si/MgO/Co₂Fe_0.4Mn_0.6Si lateral structured devices at low temperature

〇Takeo Koike¹, Mikihiko Oogane¹, Masakiyo Tsunoda¹, Yasuo Ando¹ (1.Tohoku Univ.)

Keywords:Spin injection, Heusler alloy

Spin transports between two ferromagnetic (FM) electrodes on a semiconductor (SC) channel have been demonstrated by many groups using non-local Hanle and spin-valve measurements. However, the obtained magnetoresistance ratio was considerably small because spin polarizations of the FM materials are small. For the enhancement of spin signals, Co-based Heusler alloys are promising materials as the FM electrode because of their high spin polarizations. In a previous work, we successfully fabricated B2 ordered Co₂Fe_0.4Mn_0.6Si (CFMS) films with high saturation magnetization on Si(100) substrates. In this work, we investigated post annealing temperature dependence of the local 3-terminal spin valve signals through the n-type Si channel using CFMS electrode. As a results, we obtained the L-3TSV signal of ~370 µV at 10 K for the CFMS sample with annealing temperature 350℃, which is 3 times larger than that for the CoFe.