Characterization of Heusler alloy thin film, Cu₂MnAl and Co₂MnSi, deposited by co‐sputtering method

Abstract

Abstract Thin films of Heusler alloy, Cu 2 MnAl and Co 2 MnSi were fabricated successfully, by the co‐sputtering method. Magnetic and structural properties are strongly dependent on substrate temperature. The films fabricated at room temperature show paramagnetic behaviour and amorphous or very fine crystalline feature in XRD and TEM analysis. On increasing substrate temperature, there appear polycrystalline features of L2 1 structure, accompanied by ferromagnetic properties. Also, the electrical resistivity implies that the electronic structures are heavily disturbed in the films fabricated at room temperature. These results suggest that structural ordering strongly affects the magnetic and electrical properties of Cu 2 MnAl and Co 2 MnSi. The Curie temperature and saturation magnetization of Co 2 MnSi, Cu 2 MnAl are 950 K (with extrapolation), 1100 emu/cc and 600 K, 440 emu/cc, respectively. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)