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.