Paper Title
HRTEM and MC Simulation Study of NC-TIN/A-(C,CNX) Nanocomposite Films

The grain growth in two-phase nanocomposite Ti-Cx-Ny thin films grown by reactive close-field unbalanced magnetron sputtering in an Ar-N2 gas mixture with microstructures comprising of nanocrystalline (nc-) Ti(N,C) phase surrounded by amorphous (a-) (C,CNx) phase was investigated by a combination of high-resolution transmission electron microscopy (HRTEM) and Monte Carlo (MC) simulations. The HRTEM results revealed that amorphous-free solid solution Ti(C,N) thin films exhibited polycrystallites with different sizes, orientations and irregular shapes. The grain size varied in the range between several nanometers and several decade nanometers. Further increase of C content (up to 19 at.% C) made the amorphous phase wet nanocrystallites, which strongly hindered the growth of nanocrystallites. As a result, more regular Ti(C,N) nanocrystallites with an average size of ~5 nm were found to be separated by ~0.5-nm amorphous phases. When C content was further increased (up to ~48 at.% in this study), thicker amorphous matrices were produced and followed by the formation of smaller sized grains with lognormal distribution. Our MC analysis indicated that with increasing amorphous volume fraction (i.e. increasing C content), the transformation from nc/nc grain boundary (GB)- curvature-driven growth to a/nc GB-curvature-driven growth is directly responsible for the observed grain growth from great inhomogeneity to homogeneity process. Keywords- Film Deposition; Composite Materials; Monte Carlo Methods; Structure; Transmission Electron Microscopy