The elastic moduli of ScAlO
3 perovskite, a very close structural analogue for MgSiO
3 perovskite, have been measured between 300 and 600 K using high precision ultrasonic interferometry in an internally heated gas-charged pressure vessel. This new capability for high temperature measurement of elastic wave speeds has been demonstrated on polycrystalline alumina. The temperature derivatives of elastic moduli of Al
2O
3 measured in this study agree within 15% with expectations based on published single-crystal data. For ScAlO
3 perovskite, the value of (∂
KS/∂
T)
P is −0.033 GPa K
−1 and (∂
G/∂
T)
P is −0.015 GPa K
−1. The relative magnitudes of these derivatives agree with the observation in Duffy and Anderson [Duffy, T.S., Anderson, D.L., 1989. Seismic velocities in mantle minerals and the mineralogy of the upper mantle. J. Geophys. Res. 94, 1895–1912.] that |(∂
KS/∂
T)
P| is typically about twice |(∂
G/∂
T)
P|. The value of (∂
KS/∂
T)
P for ScAlO
3 is intermediate between those inferred less directly from
V(
P,
T) studies of Fe-free and Fe- and Al-bearing MgSiO
3 perovskites [Wang, Y., Weidner, D.J., Liebermann, R.C., Zhao, Y., 1994.
P–
V–
T equation of state of (Mg,Fe)SiO
3 perovskite: constraints on composition of the lower mantle. Phys. Earth Planet. Inter. 83, 13–40; Mao, H.K., Hemley, R.J., Shu, J., Chen, L., Jephcoat, A.P., Wu, Y., Bassett, W.A., 1991. Effect of pressure, temperature and composition on the lattice parameters and density of (Mg,Fe) SiO
3 perovskite to 30 GPa. J. Geophys. Res. 91, 8069–8079; Zhang, Weidner, D., 1999. Thermal equation of state of aluminum-enriched silicate perovskite. Science 284, 782–784]. The value of |(∂
G/∂
T)|
P for ScAlO
3 is similar to those of most other mantle silicate phases but lower than the recent determination for MgSiO
3 perovskite [Sinelnikov, Y., Chen, G., Neuville, D.R., Vaughan, M.T., Liebermann, R.C., 1998. Ultrasonic shear wave velocities of MgSiO
3 perovskite at 8 GPa and 800K and lower mantle composition. Science 281, 677–679].
Combining the results from the previous studies and current measurements on ScAlO3 perovskite, we extracted the parameters (q and γ0) needed to fully specify its Mie–Grüneisen–Debye equation-of-state. In this study, we have demonstrated that acoustic measurements of KS(T), unlike V(P,T) data, tightly constrain the value of q. It is concluded that ScAlO3 has ‘normal’ γ0 (1.3) and high q (3.6). The high value of q indicates that ScAlO3 has very strong intrinsic temperature dependence of the bulk modulus; similar behaviour has been observed in measurements on Fe- and Al-bearing silicate perovskites (Mao et al., 1991; Zhang and Weidner, 1999). 相似文献