S. Vepřek

TL;DR: In this article, a concept for the design of novel nanocrystalline/amorphous composites is suggested based on recent theoretical and experimental results regarding the appearance of supermodulus phenomena in composition-modulated layered heterostructures and on a simple thermodynamic criterion for segregation in ternary nitride systems.

TL;DR: In this article, thin films of novel superhard composite materials consisting of TiN nanocrystals in an amorphous Si3N4 matrix have been prepared by means of plasma chemical vapor deposition.

TL;DR: In this article, a combined plasma CVD and PVD technique was developed for the deposition of superhard nc-TiN/c-BN nanocomposites, which reached 70 GPa and elastic modulus E/(1-ν 2 )≈585 GPa.

TL;DR: In this paper, a theoretical concept for the design of novel, nanocrystalline and thermodynamically stable materials with hardness of ≥50 GPa (about 5000 kg mm−2), elastic modulus of ≥500 GPa and a high stability against oxidation in air up to 800°C is described together with its experimental verification on several systems nc-MexN/a-Si3N4 (Me  Ti, W, V).

TL;DR: The average crystallite size, d, in the range of about 3-8nm determined from XRD by means of the Scherrer formula and integral width of the Bragg peaks compares well with that determined from the Warren-Averbach analysis as discussed by the authors.