Magnetic and electric properties of Sn-oxide/M (M=Fe, Ni, Co) multilayers

Magnetic and electronic properties of novel semiconductive-oxide/ferromagnet multilayers of Sn-oxide and ferromagnetic metals (Fe, Ni, Co), deposited with a multi-target rf magnetron sputtering system, were studied. Among the studied material systems, Co/Sn-oxide sustains well-defined layer structure and ferromagnetic property for the thinnest thickness of 1 nm. A thermionic CPP transport was observed in [Co(2 nm) /Sn-oxide (4 nm)₁₀, which activation energy was evaluated as 4.4×10^-3 erg from the thermal dependence of conductivity. Negative magnetoresistance was observed in two orthogonal directions of in-plane external fields, which confirms spin dependent transport in Sn-oxide thin film. The measured MR change is 0.6 % (δR = 0.8 Ω, R_s=140 Ω) at room temperature.