Thermodynamic study of ferrites LaMII 3Fe5O12 (MII — Mg, Ca, Sr)

Abstract

New ferrites LaMII 3Fe5O12 (MII — Mg, Ca, Sr) were obtained by high-temperature synthesis on ceramic technology. By powder X-ray diffraction established that compounds crystallize in the tetragonal singonia, the parameters of its crystal lattices are determined. The heat capacity of ferrites has been defined by dynamic calorimetric method at 298.15–673 K and detected the presence of phase transitions of type II. The equations describing the dependence in the range 298.15–673 K are derived taking into account the phase transitions.