Heteroepitaxy of ferrite‐spinel layers by CVD method

Abstract

AbstractThe nucleation mechanism, the substructure, the inner stresses, and the formation of different dislocation structures were studied in the epitaxial ferrospinel layers. Monocrystalline layers of Mg‐Mn‐, Min‐ and Li‐ferrites were grown by the CVD method in a small gap on MgO substrates. The initial growth stage begins with the formation of three‐dimensional nuclei, but after their coalescence the mechanism of layer‐to‐layer growth is realized. X‐ray topographical study shows that the layer structure up to 6 μm thick was formed by slip steps but above 10 μm by cleavage steps. The residual elastic compressive stresses studied by X‐ray tensometry are about 6 × 108 N/m2. The development of dislocation structure of layers depending on their thickness and growth conditions was studied by means of optical and scanning electron microscopy: for synthesis temperatures up to 1200 K only the dislocation sliping was observed, above 1370 K their overcreeping occurred.