Elastic constants of single-crystal transition-metal nitride films measured by line-focus acoustic microscopy

• Published in: Journal of applied physics Vol. 72; no. 5; pp. 1805 - 1811
• Main Authors: KIM, J. O, ACHENBACH, J. D, MIRKARIMI, P. B, SHINN, M, BARNETT, S. A
• Format: Journal Article
• Language: English
• Published: Woodbury, NY American Institute of Physics 01.09.1992
• Subjects: Condensed matter: structure, mechanical and thermal properties; Elasticity, elastic constants; Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Physics; Elastic constant; Elastic modulus; Niobium Nitrides; Compliance; Support; Transition metal Compounds; Acoustic wave; Epitaxial film; Experimental study; Single crystal; Inorganic compound; Wave dispersion; Thickness; Titanium Nitrides; Investigation method; Anisotropy; Acoustic microscopy; Frequency; Rayleigh wave; Vanadium Nitrides; Stiffness
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.351651

The elastic constants of single-crystal NbN, VN, and TiN films were determined from surface acoustic wave (SAW) dispersion curves obtained by the use of an acoustic microscope with a line-focus beam. Measurements were carried out for single-crystal nitride films grown on the (001) plane of single-crystal cubic-symmetric MgO substrates. The phase velocities measured as functions of the angle of propagation display the expected anisotropy. Dispersion curves of SAWs propagating along the symmetry axes were obtained by measuring the wave velocities for various film thicknesses and frequencies. Using a modified simplex method, an inversion of the SAW dispersion data yielded the elastic constants of cubic symmetry, namely c11, c12, and c44. The Rayleigh surface wave velocities calculated from the determined elastic constants and known mass densities agree well with a result measured by Brillouin scattering spectroscopy reported elsewhere.