Elastic properties of aluminate glasses via Brillouin spectroscopy

Sound wave velocities have been measured for CaAl2O4 glass and for two comp ositions along the Y2O3-Al2O3 join by Brillouin scattering spectroscopy. Th e sound speeds in these aluminate glasses range from 6.96 +/- 0.16 km/s (v( L)) and 3.81 +/- 0.05 km/s (v(T)). The corresponding bulk moduli are K = 79 GPa for CaAl2O4 glass, and 113 +/- 5 GPa for the Y2O3-Al2O3 glasses. The l atter moduli are much larger than for most silicate or aluminosilicate glas ses. The low compressibility is due to the lack of traditional network-form ing cations in the yttrium aluminate glass so that all Al-O and Y-O bonds c ontribute equally in resisting compression. (C) 1998 Published by Elsevier Science B.V. All rights reserved.