Characterization of sputtering CoFe-ITO junction for spin injection

摘要

The combination of ferromagnetic metal (FM) and semiconductor (SC) for spin injection was studied and demonstrated with FM-SC-FM junction. The semiconductor was chosen to be doped Indium-Tin-Oxide(ITO). Both ITO single-layer film and CoFe-ITO-CoFe junction were sputtering deposited. The ITO single-layer film was n-type with a small resistance of about 100 Ω/Square. I-V curves and Magnetoresistance (MR) effect of the CoFe-ITO-CoFe junction were measured at room temperature and 77 K. Results show that the CoFe forms an ohmic contact to ITO film. But at low temperature, the I-V curves show a Schottky-like characteristic, which is strongly affect by applied magnetic field. The MR effect was measured to be 1% at 77 K, which indicates a spin injection into semiconductor to be realized in this sandwich junction.