High-temperature heat capacity of Zn$_{2}$V$_{2}$O$_{7}$–Cu$_{2}$V$_{2}$O$_{7}$ solid solutions

Differential scanning calorimetry has been used to study the influence of temperature on the heat capacity of synthesized vanadates Zn$_{2}$V$_{2}$O$_{7}$, (Cu$_{0.56}$Zn$_{1.44}$)V$_{2}$O$_{7}$, and (Cu$_{1.0}$Zn$_{1.0}$)V$_{2}$O$_{7}$. It is found that dependences $C_ p= f(T)$ have extremes. The thermodynamic properties of Zn$_2$V$_2$O$_7$ have been determined.