Spin injection at CoFe/ITO heterojunction at low temperature

摘要

The study of spin injection at ferromagnetic semiconductor heterojunction (FSJ) and ferromagnetic metal-semiconductor interfaces has been of considerable interests in recent years. At low temperatures, the demonstration of spin coherent transport over large distances in n-type semiconductor[1] and the persistence of spin coherence on a sizable time scale[2] are highly promising indicators in the pursuance of the realization of "spintronics" devices utilizing the information of the spin states of electrons. The ferromagnetic and the heavily doped semiconductor vital barrier for the spin injection are due to the large mismatch in conductivities between the metal and semiconductor [3] when the spin carrier transport in a diffusive regime. Since Indiu-tin-oxide (ITO) can commonly form a good ohmic contact with ferromagnetic layer, in present work ITO was selected to fabricate a FSJ, the resistance mismatch problem referred above can expected to be solved and also the spin injection be realized.