The velocity of sound for both transverse and longitudinal waves has been measured in single crystals of pure gallium. These velocity data have been used to calculate a complete set of elastic constants for gallium at 273, 77, and 4.2 °K. A survey has also been made of the acoustic attenuation in gallium at approximately 5 MHz over the range 1.5–300 °K. The measurements were made using a transducerless method which utilizes the direct electromagnetic generation of acoustic waves at the surfaces of a metal to excite standing sound waves in a slab-shaped specimen. It is demonstrated that this technique is both convenient and sensitive: changes of 1:106 in the velocity of sound in gallium were found to be readily measurable over the range 1.5–300 °K.
We describe here a time resolved pump-probe laser technique—picosecond interferometry—which has been combined with diamond anvil cells (DAC). This method enables the measurement of the longitudinal sound velocity up to Mbar pressure for any kind of material (solids, liquids, metals, insulators). We also provide a description of picosecond acoustics data analysis in order to determine the complete set of elastic constants for single crystals. To illustrate such capabilities, results are given on the pressure dependence of the acoustic properties for prototypical cases: polycrystal (hcp-Fe-5 wt% Si up to 115 GPa) and single-crystal (Si up to 10 GPa).
A complete set of material properties of single domain 0.26Pb(In1/2Nb1/2)O3–0.46Pb(Mg1/3Nb2/3)O3–0.28PbTiO3 single crystals
