Spin dependent transport in CoFe/ITO Ohmic contact at room temperature

摘要

Spin injection from ferromagnet into semiconductor are investigated intensively recently for the purpose of the integrity of the spintronics into semiconductor devices, and moderate spin injection efficiency has been realized[1]. But the conditions in these experiment are always rigorous as low temperature or(or and) high magnetic field being adopted. The vital barrier for the spin injection is due to the large mismatch in conductivities between the metal and semiconductor[2] when the spin carrier transport in a diffusive regime(in which all the electronic devices operate). So come out certain promising routes: E. I. Rashba[3] brought forward a theory using a tunnel contacts as a solution of the conductivity mismatch problem, and the experimental confirmation has been afforded by A. T. Hanbicki et al. [4]; diluted magnetic semiconductor[5][6][7] or half-metallic ferromagnets[8][9] are also suggested as the available source of the spin polarization carriers. Here we present a heavily doped semiconductor Indium-tin-oxide(ITO) as the two dimensional electron gas(2DEG). Samples fabricated by electron beam evaporation consists of a structure of glass sub-strate/30nm ITO/30nm CoFe/15nm ITO/50nm CoFe. In addition, a two layer structure ITO/CoFe is designed for the test of the I-V relationship of the ITO/CoFe junction.