High tunability in (111)-oriented relaxor Pb_0.8Ba _0.2ZrO₃ thin film with antiferroelectric and ferroelectric two-phase coexistence

Using a sol-gel method Pb_0.8Ba_0.2ZrO₃ (PBZ) thin film with a thickness of ~320 nm was fabricated on Pt(111)/TiO _x/SiO₂/Si substrate. The analysis results of XRD, SEM, and dielectric properties revealed that this thin film is a (111)-oriented nano-scaled antiferroelectric and ferroelectric two-phase coexisted relaxor. Calculations of dielectric tunability (η) and figure-of-merit (FOM) at room temperature display a maximum value of 75% at E = 560 kV/cm and ~236, respectively. High-temperature stability (η > 75% and FOM > 230 at 560 kV/cm in the range from 300 to 380 K) and high breakdown dielectric strength (leakage current < 1 nA at 598 kV/cm) make the PBZ thin film to be an attractive material for applications of tunable devices.