Preferred orientations and epitaxial relationships of α-HgI2 thin films on (001)-KCl and (001)-Muscovite single crystals

The quantitative texture analysis of HgI2 films deposited on KCl and Muscovite single crystal substrates is reported. The lattice parameters of the films have been refined. They are close to the bulk α-HgI2 tetragonal structure. The films are strongly in-plane oriented. Complex pole figures are observed, explained after the orientation distribution calculation, using a direct method. Orientation maxima as high as 248 times the random distribution are observed for the orientation distribution, with texture index up to 44. The orientations are governed by heteroepitaxial relationships. Three relations are observed and described for each substrate, which are explained by close distance matching between the film and the substrate. Additional texture symmetry is provided by the substrate crystal-plane, four-fold in the case of KCl and six-fold for muscovite.