Evaluation of elastic properties of iron in diamond anvil cell by laser ultrasonics technique

Abstract

We propose an improved algorithm for the determination of shear wave velocity in iron under high pressure within the frame of an earlier proposed laser ultrasonics technique [1]. The modification is based on the observation that the signal identified at short propagation distances as a TT wave (the wave that is excited as the shear (T) wave at the diamond/iron interface and is reflected by the iron/diamond interface as a T wave) splits into two signals, a TT wave and another wave, which may be associated with a head wave, beginning from some threshold distance. This finding allows us to improve the accuracy of shear wave velocity determination. Statistical errors of the sample thickness and of the longitudinal and shear velocities measurements were found to be less than 2%. © 2010 IOP Publishing Ltd.