Effects of pyrolysis conditions on dielectric properties of PLZT films derived from a polyvinylpyrrolidone-modified sol–gel process

Pb0.92La0.08Zr0.52Ti0.48O3 (PLZT) films were deposited on platinized silicon substrates (Pt/Si) using a polyvinylpyrrolidone (PVP) modified sol–gel method. Pyrolysis of the green films was conducted via two methods: rapid thermal annealing (RTA) and a step-wise preheat treatment (SPT). Microstructure analysis and dielectric property characterization were performed on samples treated by these two methods. Results showed that the SPT-pyrolyzed films exhibited much better dielectric properties when compared with the RTA-pyrolyzed films. The differences in dielectric properties were correlated to microstructural features caused by the different pyrolysis conditions. High-quality PLZT films with high dielectric constant (≈860 at zero bias) and high breakdown strength (≈2.1 MV/cm) were fabricated under controlled pyrolysis conditions. This work demonstrated the potential application of this material for power electronics in electric drive vehicles.

SEM images showing the surface morphology of PLZT films derived from solutions with various PVP content and treated with either RTA (rapid thermal annealing) or SPT (step-wise preheat treatment) process.Figure optionsDownload as PowerPoint slideHighlights
► High-quality PLZT films were fabricated by using a polyvinylpyrrolidone-modified sol–gel method.
► Improved film density and integrity was achieved by employing a novel step-wise preheat treatment (SPT) process.
► Enhanced dielectric properties were correlated to the improved microstructures as a result of the SPT process.