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 (Tc) from the high-temperature paraelectric phase into the ferroelectric one did not depend on barium titanate concentration and practically coincided with Tc 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.