MORPHOLOGY AND MAGNETIC ANALYSIS OF MNSB FILMS GROWN BY HOT-WALL EPITAXY

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. I t is observed that the thinnest film has grains elongated along GaAs [ 011] and the grains in the other two thicker films exhibit two orthogo nal domains. The above microstructures of the films have a marked impa ct 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 [01 (1) over bar] (along the [1 (2) over bar.0] axis of MnSb). The largest measured values for coercivity, remanent magnetization, and squareness ratio o f the three films are found in the thinnest film, and the thickest fil m has the highest saturation magnetization. Finally, the angular varia tion of coercivity curves indicate that the magnetization reversal mec hanism of the three films is an incoherent rotation type, i.e., non-St oner-Wohlfarth type. (C) 1998 American Institute of Physics. [S0021-89 79(98)05814-9].