Brillouin scattering from acoustic excitations in TiN films on high speed steel - a stiffening system

Abstract

The elastic properties of TiN films of various thicknesses deposited on high speed steel by dc magnetron sputtering were investigated. A Green's function method was used to calculate the Brillouin scattering spectra for the stiffening situation. For large film thicknesses (h≥870 nm), the measured pseudo-surface acoustic waves and its higher modes conformed well with the calculations based on the elastic constants of the bulk TiN. Results demonstrated that the complicated variations of the composition and structure at the interface region were considered to be a major reason for the reduction in the effective elastic moduli of the thinner films.