In situ Photoemission Study of the Room Temperature Ferromagnet ZnGeP2-Mn

Abstract

The chemical states of the ZnGeP2:Mn interface which shows ferromagnetism above room temperature have been studied by photoemission spectroscopy. Mn deposition on the ZnGeP2 substrate heated to 400degreesC induced Mn substitution for Zn and then the formation of metallic Mn-Ge-P compounds. Depth profile studies have shown that Mn 3d electrons changed their character from itinerant to localized along the depth, and in the deep region, dilute divalent Mn species (< 5% Mn) was observed with a coexisting metallic Fermi edge of non-Mn 3d character. The possibility of hole doping through Mn substitution for Ge and/or Zn vacancy is discussed