Elastic constants of the SrLaAlO 4 and SrLaGaO 4 crystals measured at ultrasonic and hypersonic acoustic frequencies

Abstract

Elastic constants measured by Brillouin light-scattering experiments were compared with results estimated from the pulse–echo–overlap method for the ultrasonic frequency to find dispersion in their values. In this way Brillouin hypersonic experiments complete the ultrasonic results. The present investigation includes a careful analysis of the accuracy of the results. The measured values of elastic constants suggest a weak dispersion in acoustic wave velocities. However, given the magnitude of the experimental errors, it is difficult to conclude about the dispersion.