| Abstract: | The 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. |
