Structural and magnetic phase diagrams of epitaxial Cr-Mn alloy thin films

Abstract

We report here a systematic study of Cr-Mn alloy films that have been epitaxially stabilized on GaSb (100) using molecular beam epitaxy. The crystal structural transition between the α-Cr -type and the α-Mn -type for the Cr-Mn alloy films is observed along with changes in growth temperature, film thickness, and the ratio of Cr to Mn. Ferrimagnetism is observed in the Cr-Mn films containing the α-Mn -type phase based on the magnetic field-dependent anomalous Hall effect hysteresis and is corroborated by the magnetization hysteresis. The α-Mn -type CrMn phase at the expanded lattice parameter induces the observed ferrimagnetic ordering. The magnetic moments of Cr-Mn films can be tuned by adjusting the growth temperature, film thickness, and the ratio of Cr to Mn. Eventually, new structural and magnetic phase diagrams of the epitaxial Cr-Mn alloy films are established. The results of this study can prove helpful in both forming a comprehensive understanding of Cr-Mn alloys and in finding new applications for it in spintronic devices. © 2010 American Institute of Physics.