Phase transition behaviors of BaTiO₃–BaZrO₃ solid solutions under high direct current bias fields

The dielectric properties of the Ba(Ti_1–xZr_x)O₃ (BT_1–xZ_x) ceramics with various compositions were investigated under various DC bias fields. In BT_0.94Z_0.06 ceramics, the dielectric constants (ε) vs temperature (T) curves without DC bias showed no frequency dependence. Its DC bias dependence exhibited that with increasing DC bias fields, the dielectric constants were suppressed while phase transition peaks slightly shifted to high temperature. In BT_0.58Z_0.42 ceramics, the ε vs T curves without DC bias showed a broad peak with a clear frequency dependence, which revealed that BT_0.58Z_0.42 ceramics were the relaxor. Its DC bias dependence exhibited that with increasing DC bias fields, the dielectric constants were suppressed while the phase transition peak largely shifted to low temperatures. In BT_0.79Z_0.21 ceramics, the ε vs T curves without DC bias showed a broad peak without frequency dependence. Its DC bias dependence revealed that the dielectric peak shifted to high temperature and broadened with increasing DC bias. To explain the above phenomena, it was considered that the role of Zr ions on BT_1−xZ_x ceramics is to make the depth of the potential well shallow successively.