ELASTIC PROPERTIES OF BREAKAWAY GLASS AND LIQUID BY BRILLOUIN-SCATTERING UP TO 170-DEGREES-C

The compressional V-p wave velocity, refractive index n, and acoustic attenuation coefficient Gamma of breakaway glass and liquid have been measured by high-resolution Brillouin spectroscopy up to 170 degrees C in platelet and backscattering geometries. A marked break in the comp ressional wave velocity-temperature relationship is observed at the gl ass transition temperature of 52 degrees C consistent with the glass t ransition temperature observed in ultrasonic experiments on the same s ample. The temperature dependence of the compressional wave velocity d etermined by Brillouin scattering and ultrasonic interferometry are co mpared.