Pressure dependences of elastic moduli for geophysical minerals using the Stacey equation of state
S. K. Sharma, B. S. Sharma and R. Kumar
The reciprocal K–prime EOS due to Stacey has been found to describe adequately behaviour of materials at extreme compression. We have generalized the Stacey equation of state to compute the pressure dependences of elastic moduli for geophysical minerals such as MgO and MgSiO3 Perovskite. We have used the method adopted by Tallon for generalizing the expressions of different elastic moduli. It has been assumed that the individual elastic moduli change with pressure/compression in a manner similar to the change in bulk modulus. It is found that the results obtained in the present study for C11, C12, and C44 in case of MgO and C11, C12, , C13, C22, C23, C33 in case of MgSiO3 Perovskite are in close agreement with the available data, however, C44, C55, and C66 for MgSiO3 Perovskite present less satisfactory agreement with the available data.
Keywords: Elastic moduli, Equation of State, Geophysical minerals, MgO, MgSiO3 Perovskite.