Thermodynamic properties of Sr4Zr3O10(s)

Abstract

Standard molar Gibbs energies of formation of Sr4Zr3O10(s) have been determined for the first time by measuring Sr(g) pressures over the three phase mixture {Sr4Zr3O10(s)+SrZrO3(s)+Zr1−xOx(s)} using the Knudsen effusion mass-loss technique employing a Sartorius microbalance, model 4410, and are given as: ΔfGm(Sr4Zr3O10, s,T)±20(kJ·mol−1)=−5946.8+1.0076(T/K), (1157.5≤T/K≤1370.5). Using the molar heat capacities for Sr(s, l), Zr(s), and O2(g) from literature and that for SrZrO3(s) from our previous work, ΔfHm°(Sr4Zr3O10, s, 298.15 K) has been calculated as −(5985.4±49) kJ·mol−1. A value of ΔfHm°(Sr4Zr3O10, s, 298.15 K)=−(5972.8±44) kJ·mol−1has also been calculated using the values for the function: Φ=(Δ°TSm−Δ298.15 KTHm/T) for SrZrO3(s), Sr(g), Zr0.72O0.28(s), and Sr4Zr3O10(s) from literature. The value of −(5972.8±44) kJ·mol−1(the third-law value) is recommended for ΔfHm°(Sr4Zr3O10, s, 298.15 K).