Highly enhanced piezoelectric properties of PLZT/PVDF composite by tailoring the ceramic Curie temperature, particle size and volume fraction

• PLZT/PVDF composites were prepared by hot-press process.
• Curie temperature of PLZT is effectively reduced by substitution of Pb with La.
• PLZT/PVDF can be effectively polarized by tailoring Tc of PLZT.
• Piezoelectric properties of PLZT/PVDF are enhanced by tailoring Tc of PLZT.

Piezoelectric oxides Pb1−xLax(ZryTi1−y)1−x/4O3 (PLZT) were synthesized by the solid-state reaction process and Pb0.96La0.04(Zr0.54Ti0.46)0.99O3/polyvinylidene fluoride (PL0.04ZT/PVDF), Pb0.92La0.07(Zr0.555Ti0.445)0.9825O3/PVDF (PL0.07ZT/PVDF) composites with various particle sizes and contents (50–90 vol.%) of the ceramic phase were prepared by the hot-press process. The Curie temperature (Tc) of PLZT decreases monotonously from 312 °C to 98 °C with La content (x) increasing from 0.02 to 0.09. The polarizability of PLZT/PVDF composites increases from 39.5% (PL0.04ZT/PVDF) to 56.7% (PL0.07ZT/PVDF) when poled at 125 °C (at the vicinity of Tc of PL0.07ZT). As a result, the electrical property improvement with d33 (ɛr) from 53 pC/N (159) to 76 pC/N (222) proves that tailoring Tc of the piezoelectric ceramic to the poling temperature is a useful way to enhance the piezoelectric and dielectric properties of the ceramic/polymer composite. To further investigate the electrical properties of the 0–3 type PLZT/PVDF composite, the particle size and volume fraction of PLZT are also optimized.