Magnetic Properties and Magnetoresistance of CdMnS:Au Based Structures Prepared by Co-evaporation

Polycrystalline CdMnS and CdMnS:Au films with hexagonal structure on Si(111) substrates are prepared by co-evaporation, and exhibit ferroelectric and ferromagnetic properties, respectively. Under optimized growth conditions, CdMnS:Au samples with an average crystallite size of 90 nm and Mn concentration of 5.0 at.% are obtained, and an all-semiconductor spin valve device of Co/Au/CdMnS:Au/CdMnS/Pt is fabricated. Electrical measurement of the device reveals the clear dependence of resistance on applied magnetic field, with a relative magnetoresistance of 0.06% and a switching field of 100 Oe at 77k