SYNTHESIS, RENTGENOGRAPHICAL AND THERMODYNAMIC PROPERTIES OF FERRO-TELLURITE LuCaFeTeO

Ferro-tellurite of composition LuCaFeTeO was synthesized from oxides LuO(grade «o.p.»), TeO(«h.p.»), FeO, calcium carbonate (qualification «p. d. a.») by ceramic technology. The identity was confirmed by X-ray phase analysis method, the syngony type was determined, and the unit cell parameters, X-ray and pycnometric densities of the compound were determined. The isobaric heat capacity of tellurite was investigated by the method of dynamic calorimetry in the temperature range 298.15—673 K, and the equations of C(T) dependence were derived. Temperature dependences of thermodynamic functions S(T), H(T) - H (298.15), F(T) and heat capacity C(T) have been calculated.