Resonant ultrasound spectroscopy: applications, current status and limitations

Over the last 10 years, resonant ultrasound spectroscopy (RUS) has become a versatile laboratory technique for measuring second-order elastic constants and ultrasonic attenuation in solids. The technique is based on measuring the spectrum of mechanical resonances for a sample of known shape (usually a parallelepiped). This spectrum cannot be deconvoluted to deduce the elastic constants. Instead, an approximate spectrum is calculated from the known sample dimensions, its mass, and a set of 'guessed' elastic constants. A multidimensional minimization of the error between the measured and calculated spectra enables deducing all the elastic constants of the solid from a single frequency scan. Currently, the technique can be applied to crystals of orthorhombic symmetry (9 elastic constants) or higher using desktop computers and software developed for this purpose. (C) 2000 Published by Elsevier Science S.A.