Morphology and magnetic analysis of MnSb films grown by hot-wall epitaxy

Abstract

MnSb epitaxial layers were grown on GaAs (100) substrates by hot-wall epitaxy and the structural, morphology, and magnetic properties of the layers were examined. In this study, three films of different nominal film thicknesses were fabricated. All the films are found to be well-interconnected with low intergrain resistance values being measured. It is observed that the thinnest film has grains elongated along GaAs [011] and the grains in the other two thicker films exhibit two orthogonal domains. The above microstructures of the films have a marked impact on the easy magnetization axis. The easy magnetization axis of the thinnest film is found to be along that of the elongation direction of the grains and that for the thickest film is along GaAs [011̄] (along the [12̄.0] axis of MnSb). The largest measured values for coercivity, remanent magnetization, and squareness ratio of the three films are found in the thinnest film, and the thickest film has the highest saturation magnetization. Finally, the angular variation of coercivity curves indicate that the magnetization reversal mechanism of the three films is an incoherent rotation type, i.e., non-Stoner–Wohlfarth type.