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 constant s 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 elas tic constants. Instead, an approximate spectrum is calculated from the know n sample dimensions, its mass, and a set of 'guessed' elastic constants. A multidimensional minimization of the error between the measured and calcula ted 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 comp uters and software developed for this purpose. (C) 2000 Published by Elsevi er Science S.A.