Equation of state and thermoelastic properties of Mg2SiO4

In the present study we have determined the P-V-T relationships for Mg2SiO4 which remains stable only below 60 GPa at 300 K, 55 GPa at 500 K, 44 GPa at 1000 K, 33 GPa at 1500 K, 15 GPa at 2000K, 13 GPa at 2500 K. The calculations have been performed using the Holzapfel adapted polynomial expansion of second order (AP2) EOS based on the Thomas Fermi model at extreme compression in the limit of infinite pressure. In addition to the P-VT results, we have also calculated the bulk modulus and its first as well as second order pressure derivatives. We have used free volume theory to determine thermoelastic properties of Mg2SiO4. The Gruneisen parameter and its volume derivative have been determined using the pressure derivatives of bulk modulus. The results have been discussed and compared with the available data reported in the literature.