Diffuse ferroelectric phase transition in SrTiO$_3$–BiScO$_3$

Ceramic samples of the $(1-x)$SrTiO$_3$–$(x)$BiScO$_3$ system with $x$ = 0, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 have been synthesized for the first time. X-ray diffraction data showed that the samples with $x$ = 0.2, 0.3, and 0.4 at room temperature comprise the mixture of two phases: (i) cubic nonpolar phase with Pm3m structure and (ii) tetragonal polar phase with P4mm structure. The temperature dependences of permittivity and dielectric loss tangent of these samples exhibit anomalies characteristic of ferroelectrics with diffuse phase transitions.