Effect of forming pressures on electric properties of piezoelectric ceramic/sulphoaluminate cement composites

Cement-based piezoelectric composites with 0-3 connectivity are fabricated from 0.08Pb(Li1/4Nb3/4)O3 · 0.47PbTiO3 · 0.45PbZrO3(PLN) and sulphoaluminate cement by compressing technique. Piezoelectric and dielectric properties of the composites under different forming pressures are measured and investigated. The results show that the composites prepared by compression technique exhibit excellent piezoelectric and dielectric properties. With increasing of forming pressure, the piezoelectric strain coefficient and dielectric constant increase, but the forming pressure has insignificant influence on electromechanical coupling property of the composites. The dielectric constant decreases sharply with increasing frequency from 40 kHz to 100 kHz, which is mainly due to interfacial polarization in the composite and polarization in the cement matrix. At high frequency, the composites show excellent dielectric frequency stability. The composite prepared at high pressure is favorable to the polarization of the ion at low frequency.