Thermodynamic properties of crystalline magnesium zirconium phosphate

Heat capacity C p ∘ ( T ) of crystalline magnesium zirconium phosphate was measured between 6 and 815 K. The experimental data obtained were used to calculate the standard thermodynamic functions C p ∘ ( T ), H °( T ) − H °(0), S °( T ), G °( T ) − H °(0) over the temperature ranging from T → 0 to 810 K and standard entropy of formation at 298.15 K. The fractal dimension of Mg 0.5 Zr 2 (PO 4 ) 3 was calculated from experimental data on the low-temperature (6 ≤ T /K ≤ 50) heat capacity, and the topology of the phosphate’s structure was estimated. Thermodynamic properties of structurally related phosphates M 0.5 Zr 2 (PO 4 ) 3 (M = Mg, Ca, Sr, Ba, Ni) were compared.