Transmission electron microscopy of AIN/TiN superlattice coatings fabricated by pulsed laser deposition

Multilayered AlN/TiN superlattice coatings with superlattice periods from 0.6 to 20 nm were fabricated on single crystal Si substrates by pulsed laser deposition at substrate temperatures from 25°C to 700°C. Pseudomorphic stabilization of the non-equilibrium Bl-AIN phase in these coatings was studied by cross-sectional high-resolution transmission electron microscopy (TEM) and selected area electron diffraction. Super lattice coatings with nanometer scale periodicity of constituent layers are an emerging class of artificially engineered materials that continue to attract great interest in science and industry. The periodicity of these layered materials introduces unique mechanical optical and other properties that are closely related to the structure of the individual layers and interfaces. The specimens for cross-sectional TEM analysis were prepared by the conventional method, that is, by "sandwich-gluing", grinding, dimpling, and ion milling. A JEOL-2010F TEM with a point resolution of 0.194 nm operated at 200 kV was used for microstructural and selected area electron diffraction studies.