Antiferroelectric/ferroelectric phase transitions in Pb(Hf_1-xTi_x)O₃ ceramics with low Ti content

The phase transition behavior of Pb(Hf_1-xTi_x)O₃ (PHT) ceramics with low Ti content (x = 0.02–0.06) was systematically investigated. Results reveal that increasing Ti content induces the transition from the antiferroelectric (AFE) to the ferroelectric (FE) phase, with the phase boundary located near x = 0.05 (95/5 composition). For PHT 98/2, a dielectric anomaly at 125 °C corresponds to an AFE I → AFE II transition. In PHT 96/4, a high-temperature ferroelectric phase was identified, with a sequential phase evolution of AFE → FE → PE upon heating. PHT 95/5 exhibits clear ferroelectric behavior but retains a partial AFE component, resulting in a non-monotonic temperature dependence of remnant polarization (P_r). These findings suggest that the AFE/FE phase boundary in the PHT system lies near 95/5 and that its phase transition characteristics closely resemble those observed in Pb(Zr_1-xTi_x)O₃ (PZT)-based materials.