Magnetic and Electrical Properties of Heusler Alloy Co2MnSi Thin Films Grown on Ge(001) Substrates via an Al2O3 Tunnel Barrier

Abstract

Heusler alloy Co2MnSi/Al2O3 heterostructures on single-crystal Ge(001) substrates were prepared through magnetron sputtering for both Co2MnSi and Al2O3 thin films as a promising candidate for future-generation semiconductor-based spintronic devices. Sufficiently high saturation magnetization 781 emu/cm3 was obtained for the Co2MnSi thin film. Furthermore, the current versus voltage (I-V) characteristics showed that the tunneling conduction was dominant in Co2MnSi/Al2O3 (2 nm)/Ge(001) heterostructure and the I-V characteristics were slightly dependent on temperature. The conductance versus voltage (dI/dV-V) characteristics indicated that the potential barrier height at the Co2MnSi/Al2O3 interface was almost equal to that at the n-Ge/Al2O3 interface for the prepared Co2MnSi/Al2O3/Ge(001) heterostructure.