Effects of magnetic field treatment on dielectric properties of CCTO@Ni/PVDF composite with low concentration of ceramic fillers

Q G Chi,X Wang,J F Dong,Y Chen,Y Cui,L Gao,Q Q Lei

doi:10.1063/1.4935270

Abstract

Using melt mixing, we produced a ceramic/polymer composite with a matrix of polyvinylidene fluoride (PVDF) and a filler of 5 vol.% Ni-deposited CaCu3Ti4O12 core-shell ceramic particles (CCTO@Ni), and studied its prominent dielectric characteristics for the first. Its phase composition and morphology were analyzed by X-ray diffraction and scanning electron microscopy, respectively. After treating the composite films with various durations of a magnetic field treatment, we compared their dielectric properties. We found that the CCTO@Ni ceramic had a typical urchin-like core-shell structure, and that different durations of the magnetic field treatment produced different distributions of ceramic particles in the PVDF matrix. The dielectric permittivity of the untreated CCTO@Ni/PVDF composite was 20% higher than that of neat PVDF, and it had a low loss tangent. However, only the composite treated for 30 min in the magnetic field had an ultra-high dielectric permittivity of 1.41 × 104 at 10 Hz, three orders of magnitude higher than the untreated composite, which declined dramatically with increasing frequency, accompanied by an insulating-conducting phase transition and an increase in loss tangent. Our results demonstrate that changes in the dielectric properties of PVDF composites with magnetic field treatment are closely related to the percolation effect and interfacial polarization.

Highlights

Ceramic materials with a high dielectric permittivity, such as oxides with perovskite and related structures, are widely used in embedded capacitors, electroactive devices, and memory devices.[1,2,3,4] To use ceramic materials with a high dielectric permittivity in electronic components, it is important to decrease the size of electronic devices
We fabricated CCTO@Ni ceramic particles, depositing the Ni nanoparticles via electroless plating, and produced CCTO@Ni/polyvinylidene fluoride (PVDF) composites with a low filler concentration of 5 vol.% by melt mixing
We studied the phase compositions and morphologies of the PVDF composites by XRD and SEM, respectively, and investigated how a magnetic field treatment affected their dielectric properties

Summary

INTRODUCTION

Ceramic materials with a high dielectric permittivity, such as oxides with perovskite and related structures, are widely used in embedded capacitors, electroactive devices, and memory devices.[1,2,3,4] To use ceramic materials with a high dielectric permittivity in electronic components, it is important to decrease the size of electronic devices. We used polyvinylidene fluoride (PVDF) as the matrix polymer because of its excellent ferroelectric, dielectric, and piezoelectric properties, as well as its good chemical, thermal, and mechanical stability.[8,9,14] The PVDF matrix was mixed with CCTO@Ni particles via melt mixing to produce CCTO@Ni/PVDF composite films with a filler loading of 5 vol.%, which we exposed to a magnetic field treatment at high temperature Using these specimens, we studied how the magnetic field treatment affected the dielectric properties of the composite films for the first

EXPERIMENTAL DETAILS

Structural analysis of ceramic fillers and PVDF composites

CONCLUSION