Thermodynamic Data of Gadolinium–Strontium Phosphate

Gadolinium–strontium phosphate with the eulytite structure was synthesized. Its structure refinement was performed applying the Rietveld method. The isobaric heat capacities of phosphate Sr3Gd(PO4)3 have been measured from T = 6 to 800 K by adiabatic vacuum and differential scanning calorimetry. The standard thermodynamic functions Cp,m0, [Hmo(T) – Hmo(6)], [Smo(T) – Smo(6)], and Φmo in the range of T → 6–800 K were calculated from the experimental data. Thermal expansion of phosphate using X-ray diffraction was studied in the temperature range 298–473 K. The linear thermal expansion coefficient was α = 12.1 × 10–6 K–1.