Local magnetism of Co2MnSn Heusler alloy films and magnetoresistance of Co2MnSn-based magnetic tunnel junctions

Abstract

Co2MnSn Heusler alloy films were prepared by atomically controlled alternate deposition on MgO(001) substrates and the local magnetism was investigated using 119Sn Mössbauer spectroscopy. It turned out that the magnetic environments around the Sn sites in the films prepared by this method are uniform in comparison with those in bulk alloys prepared by arc melting. The local uniformity around the Sn sites depends on the growth temperature. The magnetoresistance of the magnetic tunnel junctions with a Co2MnSn/MgO/ Co2MnSn/Co structure, where the Co 2MnSn layers were prepared by the same method, was also examined. Tunneling magnetoresistance effect has been observed for the samples where the local magnetism is relatively uniform, although the observed ratio is not so large at the present stage. © 2010 IOP Publishing Ltd.