Stabilization of the NOP ferroelectric phase in potassium nitrate–barium titanate ferroelectric composites

The study of temperature evolution of KNO₃ (NOP) structure in ferroelectric (1−x)KNO₃ + (x)BaTiO₃ composites with BaTiO₃ concentrations х = 0.25, 0.50 and 0.53 has been carried out on cooling with the use of the neutron diffraction technique. It was shown that, on cooling, the phase transition temperature (T_c) from the high-temperature paraelectric phase into the ferroelectric one did not depend on barium titanate concentration and practically coincided with T_c for pure NOP. Moreover, it was found that the admixture of BaTiO₃ essentially enlarged the temperature range of NOP ferroelectric phase stability in the composites with BaTiO₃ concentrations x = 0.25 and 0.50. The suppression of the ferroelectric phase was observed for the composite with x = 0.53.