Synthesis, Crystal Structure, and Thermodynamic Properties of CuSm2Ge2O8

DOI: https://doi.org/10.1134/S0036023621120020

Copper samarium germanate CuSm2Ge2O8 have been synthesized by the ceramic method from CuO, Sm2O3, and GeO2 in air at the final calcination temperature 1273 K (200 h), and its crystal structure has been determined (space group Cm; a = 9.7592(2) Å, b = 15.2608(4) Å, c = 8.2502(2) Å, β = 148.2566(8)°, V = 646.46(3) Å3). The temperature dependence of the molar heat capacity Cp = f(T) measured in the temperature range 350–1000 K shows a maximum at Tmax = 498.5 K caused by the phase transition. Thermodynamic properties have been calculated from experimental data.