Dielectric Properties of Composite PZT Films with Distinct Phase-Transition Temperatures via Aerosol Deposition

With the increasing demand for ceramic-based capacitors in energy storage and electronics, ferroelectrics have gained attention due to their high dielectric coefficient. However, near the phase-transition temperature, a significant variation in dielectric coefficient leads to reduced temperature stability and degradation of electrical properties, limiting their applications. To address this, composite films with multiple phase-transition temperatures can provide a stable dielectric response over a broad temperature range. Conventional ceramic processing cannot achieve this due to interdiffusion during high-temperature sintering. To overcome this, we utilized the aerosol deposition (AD) process, which enables the fabrication of high-density ceramic films at room temperature while preserving the distinct Curie temperatures (<i>T_c</i>) of different compositions. We prepared composite films with three PZT compositions: Pb(Zr_0.2Ti_0.8)O₃, Pb(Zr_0.52Ti_0.48)O₃, and Pb(Zr_0.8Ti_0.2)O₃. Compared to single-phase Pb(Zr_0.52Ti_0.48)O₃, the composite film exhibited a higher dielectric coefficient with reduced variation across a broad temperature range due to overlapping phase transitions. The AD-fabricated composite PZT films offer enhanced thermal stability, making them suitable for temperature-sensitive applications such as compact power electronics and portable devices.