First-principles calculations for the elastic properties of nanostructured superhard TiN SixNy superlattices

The authors report the first-principles density-functional calculations for the structure and the elastic properties of superlattices containing nanoscale crystalline titanium nitride (TiN) and thin layer of silicon nitride. The authors found that the elastic properties are strongly dependent on the size of the components. Superlattices with TiN thickness smaller than 2.5 nm have far smaller values of bulk and shear moduli than bulk crystalline TiN, while ∼3 nm TiN can make the superlattice have the elastic properties close to those of crystalline TiN. © 2007 American Institute of Physics.