Effects of Carbon Nanofiber on Dielectric Properties of PMN/CNFs/EP Composites

A kind of new composite material composed of piezoelectric ceramic lead magnesium niobate-lead zirconate-lead titanate (PMN)/carbon nanofibers (CNFs)/epoxy resin (EP) were prepared by a resin casting method. The effects of carbon nanofibers on dielectric properties of PMN/CNFs/EP composites were investigated in this paper. The concetration of CNFs had significant effects on dielectric constant, dielectric loss, dielectric frequency dependence and dielectric temperature dependence of PMN/CNFs/EP composites. When the content of CNFs increased from 0 to 0.8 wt% of the epoxy resin, the dielectric constant at 1 kHz increased sharply from 13.6 to 158, and the dielectric loss increased from 0.0524 to 2.59. In plots of the dielectric constant against frequency and dielectric loss against frequency, the dielectric constant and dielectric loss reduced dramatically at lower frequency ranging from zero to about 10(5) Hz, then approach to be stable at frequency higher than 10(5) Hz. Moreover, as to the effects of temperature on dielectric constant and dielectric loss of PMN/CNFs/EP composites, the dielectric constant of composite increased ranging from 25 degrees C to 160 degrees C, and the dielectric loss of composite also showed increase besides that with CNFs content 0.8 wt%.