Soft X-Ray Spectroscopy Study of Co-Substituted Mn-Based Heusler Film of Mn3-xCoxGa (x = 0.56)

摘要

The electronic structure of Mn3-xCoxGa (x = 0.56) film, which is a candidate material for a half-metallic ferrimagnet, has been investigated by employing soft X-ray absorption spectroscopy (XAS), soft X-ray magnetic dichroism (XMCD), and photoemission spectroscopy (PES). According to Mn and Co 2p XAS measurements, Mn ions are divalent and have covalent bonding, while most of the substituted Co ions are in metallic states. The Co 2p XMCD spectrum of Mn3-xCoxGa (x = 0.56) film is very similar to that of Co metal, supporting the finding of Co 2p XAS. Finite XMCD signals are found in both Co and Mn 2p XMCD spectra, but the intensity of the Mn 2p XMCD is much weaker than that of Co 2p XMCD. XMCD measurements reveal that the substituted Co ions in Mn3-xCoxGa (x = 0.56) form ferromagnetic metallic clusters and induce weak polarization in Mn ions. Hence, this study suggests that ferromagnetic metallic Co clusters play an important role in determining the magnetic properties of Mn3-xCoxGa (x = 0.56) films.