COMPLEX XRD MICROSTRUCTURAL STUDIES OF HARD COATINGS APPLIED TO PVD-DEPOSITED TIN FILMS .2. TRANSITION FROM POROUS TO COMPACT FILMS AND MICROSTRUCTURAL INHOMOGENEITY OF THE LAYERS

Transition from porous to compact microstructure of magnetron deposite d TiN films with increasing energy of incoming particles is associated with the changes of stress and strain. This is studied by conventiona l powder diffractometry in Bragg-Brentano geometry, by asymmetric diff raction used for stress measurement in the so-called Omega-and psi-gon iometer geometries and by the Seemann-Bohlin diffractometry. The chang es of lattice parameters and preferred orientation are investigated as well. The results are discussed from several points of view: elastici ty theory, lattice defects and heterogeneous microstructure of the fil ms. The heterogeneity seems to be an important reason for specific eff ects of lattice parameters and X-ray diffraction line broadening aniso tropy. The crystallite group method (CGM) is used for the evaluation o f stress and crystallite size and reveals the microstructural inhomoge neity. The importance of the orientation of crystallite with respect t o the surface for its real structure is further confirmed by the measu rement on freestanding film.