High temperature heat capacity of germanate CaEr$_2$Ge$_4$O$_{12}$

According to the standard ceramic technology, CaEr$_2$Ge$_4$O$_{12}$ germanate was obtained from the initial oxides of CaO, Er$_2$O$_3$ and GeO$_2$ by sequential firing in air in the temperature range 1223–1423 K. Its crystal structure was determined using X-ray diffraction (e. g. $P4/nbm$; $a$ = 9.97390(8) $\mathring{\mathrm{A}}$, $b$ = 5.06017(5) $\mathring{\mathrm{A}}$, $V$ = 503.38(1) $\mathring{\mathrm{A}}^3$). The high-temperature heat capacity in the range 320–1050 K was measured by differential scanning calorimetry. Thermodynamic characteristics are calculated using experimental $C_p(T)$ data.