CRYSTAL-STRUCTURE OF PBTE FILMS GROWN ON KCL SUBSTRATES BY LASER-ASSISTED DEPOSITION

The surface and volume crystal structure of PbTe and PbTe: Cr films deposited by laser-assisted deposition (LAD) on KCl substrates were investigated by reflectance electron and x-ray diffraction. It is found that the crystal structure of the films changes along their thickness. In the initial stage of growth, formation of the metastable phase or phases of the material (depending on the substrate temperature) takes place. At a certain thickness the growth with the metastable phases changes to growth with the stable phase Thus films with comparable thicknesses of the sublayers with metastable and stable phases represent heterophase junctions. The growth mechanism of these films was semiquantitatively interpreted on the grounds of Sirota's considerations concerning the conditions for the realization of Ostwald's step law.