Abstract
By method of dynamic calorimetry, in the temperature range between 298,15 and 673 K, isobaric heat capacity of polycrystalline ferrites Bі2СаFe4O10, BіMgFe2O5.5, Bі2MgFe4O10 was experimentally studied. Mathematical processing of experimental data made it possible to derive polynomial equation of temperature dependence of ferrites heat capacity for respective temperature ranges, in dependencies C0p~f (T) of ferrite Bі2СаFe4O10 a jump was detected in heat capacity at 625K associated with phase transitions of type II. The values of the thermodynamic functions C0p(Т), H0(T) – Н0(298,15), C0(T), Fhh(Т) have been calculated. Standard values of thermodynamic functions were determined using the method of ion increments. The results obtained broaden thermodynamic data bank for complex inorganic crystalline compounds.