A new three-phase PZT C/PVC composite comprising PZT(50 vol%),nanocrystalline PVC (50 vol%) and a small volume fraction f of black(C0was prepared by the hot-pressing technique.The dielectric property of the comp...A new three-phase PZT C/PVC composite comprising PZT(50 vol%),nanocrystalline PVC (50 vol%) and a small volume fraction f of black(C0was prepared by the hot-pressing technique.The dielectric property of the composite as α function of the frequency and the dielectric and piezoelectric properties as α function of the volume fraction f of C were studied.The measured dielectric property demonstrates that α percolation transition occurs in the three-phase composites as in normal two-phase metal-insulator continuum media.The dielectric constant varies slightly with f at f〈0.1 and increases rapidly when f is close to the percolation threshold at 1kHz.The optimum properties were obtained for f=0.5 before the percolation threshold in the PZT/C/PVC(50/f/(50-f)vol%)composite with its d33(20pC/N) being 50% higher than that of the PZT/PVC(50/50vol%),and its g33(47.23×10^-3Vm/N)and Kp(0.25) much higher than the earlier reported values,XRD patterns and P-E hysteresis loops were used to interpret the experimental results.展开更多
文摘A new three-phase PZT C/PVC composite comprising PZT(50 vol%),nanocrystalline PVC (50 vol%) and a small volume fraction f of black(C0was prepared by the hot-pressing technique.The dielectric property of the composite as α function of the frequency and the dielectric and piezoelectric properties as α function of the volume fraction f of C were studied.The measured dielectric property demonstrates that α percolation transition occurs in the three-phase composites as in normal two-phase metal-insulator continuum media.The dielectric constant varies slightly with f at f〈0.1 and increases rapidly when f is close to the percolation threshold at 1kHz.The optimum properties were obtained for f=0.5 before the percolation threshold in the PZT/C/PVC(50/f/(50-f)vol%)composite with its d33(20pC/N) being 50% higher than that of the PZT/PVC(50/50vol%),and its g33(47.23×10^-3Vm/N)and Kp(0.25) much higher than the earlier reported values,XRD patterns and P-E hysteresis loops were used to interpret the experimental results.