Synthesis of the novel perovskite-type oxyfluoride PbScO2F under high pressure and high temperature

We synthesized a novel perovskite-type oxyfluoride, PbScO₂F, and investigated its crystal structure, thermal stability and dielectric properties. PbScO₂F has a cubic perovskite-type structure with Pb ions displaced from the ideal A-site positions along the 〈110〉 direction. By thermal gravity and differential thermal analyses, we found that this compound is stable up to 963 K (690 °C) under ambient atmosphere. The dielectric permittivity of PbScO₂F is approximately 80, at room temperature, which is almost the same as KTiO₂F and smaller than that of PbFeO₂F. Furthermore, an anomaly in the dielectric permittivity was observed in the vicinity of 100 K that seems to be related to the displacement of the Pb ions.