Elastic, vibrational, and thermodynamic properties of Sr10(PO4)6F2 and Ca10(PO4)6F2 from first principles

Elastic, vibrational, and thermodynamic properties of Sr₁₀(PO₄)₆F₂ and Ca₁₀(PO₄)₆F₂ from first principles

Kong Xianggang¹, Yuan Zhihong¹, Yu You², Gao Tao^{1, 3, †}, Ma Shenggui¹

(color online) The thermodynamic properties of Sr-FAP and Ca-FAP. (a) Helmholtz free energy F, (b) the internal energy E– , (c) the entropy S, (d) the specific heat exp1, exp2, and exp3 experimental data from Ref. [9], Ref. [11], and Ref. [14], respectively.