Spin-dependent intergranular transport in highly spin-polarized Co1−xFexS2 thin films

Abstract

Magnetic and magnetotransport measurements on polycrystalline thin film Co1−xFexS2, a system that exhibits tunable conduction electron spin polarization in bulk, are reported. The films exhibit a low field hysteretic magnetoresistance (MR) due to spin-dependent intergranular tunneling, thus providing a simple probe of the spin polarization. The MR increases rapidly with x, saturating as the magnetization reaches 1.0μB/Co, demonstrating that high, doping tunable, spin polarization can be readily achieved in thin films synthesized by simple methods. Quantitative estimates yield spin polarizations as high as 90%.