Calculation of thermal capacities of nitrides of the 4A subgroup metals from infrared obsorption spectra and elasticity constants

IR absorption spectra of HA subgroup metal nitrides of variable composition have been studied. Calculation method for the temperature dependence of isobar heat capacity of titanium, zirconium and hafnium nitrides according to IR absorption spectra and elasticity constants is suggested. A good agreement between calculation and experimental values permits to assess with enough reliability the values of thermal capacity of the nitrides and other isostructural phases up to the temperatures of their melting