Thermal expansion Of γ Mg2SiO4

Abstract

Thermal expansion of γ-Mg2SiO4 was measured with X-ray powder diffraction method up to 750°C at atmospheric pressure. The data are analyzed in terms of Grγneisen's theory of thermal expansion and Grγneisen's parameter is obtained to be 1.27. Volume thermal expansion coefficient is 19 at 20°C and 27 at 500°C in unit of 10-6/K. These values are compared with those of γ-Fe2SiO4, MgAl2O4 and other spinel type compounds, and it is suggested that the anharmonic properties of γ-(Mg, Fe)2SiO4 may be very close to those of MgAl2O4. © 1979, The Seismological Society of Japan, The Volcanological Society of Japan, The Geodetic Society of Japan. All rights reserved.