Methods of evaluation of second Gruneisen constant and Anderson-Gruneisen constant

Abstract

The second Gruneisen constant Q ≡[∂ln γ_g/∂ln V]_T and Anderson-Gruneisen constant δ_T[≡ -(1/αK_T)∂K_T/∂T]_P have been the subject of various investigations. In this paper we calculate γ'_g≡ (∂γ_g/∂P)_T, c'₁≡ (∂c₁/∂P) ≡{∂/∂P(∂K_T/∂P)}_T, Q and δ_T for Cd, As₂S₃ and C₆₀. We used Thurston's method, the Delanoy Coutris method, Bardeen's potential function and the Girifalco potential function (GPF) to derive these properties. Four methods have been applied for Cd in the evaluation of γ'g. The results obtained by three methods agree very well, while that from the fourth method is found to give a higher value. A relation between γ'_g and Q has been derived. We also compute these properties for As₂S₃ and C₆₀. In this connection, we point out that the present methods give reasonably good values consistent with each other. It is interesting to note that γ_g^th obtained via the GPF scheme and that given by White et al. [29] are in close agreement with each other and therefore used in the evaluation of Q. We used the value of White et al. for γ_g^th (external).