Determination of elastic properties of surface layers and coatings by resonant ultrasound spectroscopy

This paper deals with determination of in-plane elastic constants of thin layers deposited on substrates. Modified resonant ultrasound spectroscopy is used to measure resonant spectra before and after layer deposition . These two spectra are compared and changes in the position of the resonant peaks are associated with layer properties. It is shown that for thin layers either the elastic moduli or the surface mass density can be determined, providing the complementary information (the surface mass density for the determination of the moduli, the elastic moduli for the determination of the surface mass density) is known. As an experimental demonstration of this approach, the elastic moduli of diamond-like-carbon film deposited on a silicon substrate and the surface mass density of a thin spray paint on a silicon substrate are determined.