Thermodynamic properties of ytterbium titanate

The isobaric heat capacity of a single-phase sample of ytterbium titanate of pyrochlore structural type synthesized and characterized by XRD, SEM, and EDX methods in the temperature range 2–1869 K is measured for the first time. The existence of magnetic transformation at < 20 K and the absence of structural transformations in the entire region of existence of Yb2Ti2O7 are confirmed. Thermodynamic functions, viz. the entropy and the enthalpy increment and the Gibbs free energy of formation of Yb2Ti2O7 from elements and binary oxides at 298.15 K are calculated. The contribution to the heat capacity of the Schottky anomaly is estimated.