“…Compared to the undoped KNN samples, the peaks of the samples became progressively wider with increasing doping, which was considered evidence of the transition from ferroelectrics to relaxed ferroelectrics. 33 The sample exhibits two dielectric anomaly peaks at 205 °C and 401 °C, representing the transition from orthorhombic to tetragonal phase and from tetragonal to cubic phase, respectively, 36 which means that the practical polarization effect of the sample can be maintained to about 401 °C.…”