High Curie Temperature in Epitaxial D022–Mn3−xGa Ultrathin Films

Abstract

The D0[Formula: see text]–Mn3Ga ferrimagnet promises potential applications in spintronics due to its low magnetization, strong perpendicular magnetic anisotropy and high Curie temperature. In the form of thin and thick films, these properties are preserved. Here, we report on the structural and magnetic characterization of epitaxial D0[Formula: see text]–Mn[Formula: see text]Ga ultrathin films with thicknesses of 2[Formula: see text]nm, 5[Formula: see text]nm and 8[Formula: see text]nm grown on Cr buffer layers by magnetron sputtering. We found that the films are perfect single crystals with flat surfaces and Curie temperatures higher than 300[Formula: see text]K. The 2[Formula: see text]nm-thick ultrathin film has higher magnetization than that of the thicker films, likely due to uncompensated ferrimagnetic planes, along the c-axis, linked to the surface roughness at the atomic scale. These properties highly suit the requirements for the elaboration of spintronic devices such as magnetic tunnel junctions.