Sound Velocity Measurement of Stishovite at High Pressures up to 19 GPa

Abstract:

An experimental system for measurement of the elastic wave velocities of solid polycrystalline samples at high pressures has been installed at the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Wuhan). The ultrasonic system with LiNbO₃ transducer can both generate and receive high frequency (MHz) signal. Combination with a Walker-type multianvil, the travel time through the polycrystalline sample at high pressures can be obtained. We carried out sound velocity measurements on polycrystalline stishovite up to 19 GPa at room temperature. And the experimental result shows an acoustic softening at high pressures. The experimental technique provides the offline experimental measurement of various materials to the high pressures corresponding to the Earth's mantle transition zone.