Heat Capacity of the RBiGeO5(R = Sm–Yb, Y) and$$\left( {{\text{R}}_{{1 - x}}^{1}{\text{R}}_{x}^{2}} \right)$$BiGeO5 (R1 = Y; R2 = Pr, Nd) Germanates

The RxBi2 – xGeO5 (R = Sm–Yb, Y) and $$\left( {{\text{R}}_{{1\,\, - \,\,x}}^{1}{\text{R}}_{x}^{2}} \right)$$ BiGeO5 (R1 = Y, R2 = Pr, Nd) germanates have been prepared by solid-state reactions, by sequential firing of oxide mixtures in air in the temperature range 1003–1223 K. Their heat capacity has been determined by differential scanning calorimetry. The Cp(T) data have been shown to be well represented by the classic Maier–Kelley equation in the range 350–1000 K.