High-temperature studies of surface acoustic wave velocities in silicon by Brillouin scattering

The angular dependence of surface acoustic wave (SAW) velocities at high temperatures has been investigated by means of Brillouin scattering. The measurements were performed at temperatures up to 800 degrees C on the (001) surface of a silicon single crystal. The bulk elastic constants of silicon have been extracted from the data by performing a least-squares fit of calculated surface wave velocities to the measured angular dependence. There is good agreement between these results and existing ultrasonic measurements of the silicon elastic constants in this temperature range. This demonstrates the value of the technique for measurement of the high-temperature elastic properties of opaque materials.