Interfacial engineering of PZT/PVDF composites via insulating MgO as an interlayer towards enhanced dielectric performances

Polymer dielectrics with synergistic large dielectric constant (ε′) and high breakdown field strength (Eb) have important applications in electronics device and electrical industry. In this work, to enhance the integrated dielectric characteristics of lead zirconate titanate (PZT)/poly(vinylidene fluoride) (PVDF), an insulating magnesia (MgO) shell was constructed on the surface of PZT via a facile chemical precipitation, and the prepared core@shell structured PZT@MgO particles were composited with PVDF to anticipate both high ε′ and Eb but low loss. We explored how the filler loading and MgO shell thickness, frequency affect the dielectric performances of PZT/PVDF composites. The results confirm that the PZT@MgO/PVDF composites show simultaneously improved ε′ and Eb along with low loss over the pristine PZT/PVDF because the MgO interlayer induces multiple-scale polarizations in PZT@MgO/PVDF and clearly boosts the Eb due to markedly prohibited charge injection and migration and electrical branch growth. The optimized ε′ and Eb in composites can be realized by controlling the MgO shell thickness. The theoretic fitting of experimental results by the Havriliak-Negami equation further uncovers the MgO shell’ impact on the polarization mechanism and expounds the inhibiting effect on carrier migration across the composites. The resulting PZT@MgO/PVDF composite dielectrics having both high ε′ and Eb but extremely low loss, display appealing uses in the electrical industries.