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Experiments show that the elastic constants of single-crystal nitride films produced on substrates of single-crystal cubic-symmetric magnesium oxide (MgO) are of the cubic symmetry of c11, c12 and c44. Line focus acoustic microscopy was used to study surface acoustic wave (SAW) dispersion curves from single crystal films of NbN, TiN and VN. The Rayleigh wave strengths measured from the elastic constants concurred with earlier reports.

A study was conducted on the elastic properties of TiN/(VxNb1-x)N superlattices. Brillouin scattering was used to measure the single-crystal lattice-matched superlattices. Results show that surface wave velocities are independent of superlattice wavelength and thus indicates the absence of any anomaly in the c44 elastic constant. Further observations also showed that the average lattice spacing does not vary with wavelength. The results of the study provided preliminary evidence that elastic anomalies do not cause large hardness enhancements in nitride superlattices.