Dielectric characteristics and polarization response of lead-free ferroelectric (Bi0.5Na0.5)0.94Ba0.06TiO3-P(VDF-TrFE) 0-3 composites

Bismuth sodium barium titanate/poly(vinylidene fluoride-trifluoroethylene) 70/30 [(Bi0.5Na0.5)(0.94)Ba0.06TiO3-P(VDF-TrFE)] 0-3 composites were prepared by a hot-press method for different volume fractions of (Bi0.5Na0.5)(0.94)Ba0.06TiO3 ceramic powder in a P(VDF-TrFE) 70/30 copolymer matrix. The relative permittivity and dielectric loss of the composites increased with increase in the volume fraction of the ceramics, which well follows the Bruggeman model. The polarization responses of the composites were strongly dependent on the ceramic volume fraction. The composites with a higher ceramic volume fraction showed an increase in remanent polarization. At room temperature, a 0.3(Bi0.5Na0.5)(0.94)Ba0.06TiO3-0.7P(VDF-TrFE) composite showed a relative permittivity epsilon(r) = 30, remanent polarization P-r = 12 muC/cm(2) and coercive field E-c = 44 kV/mm. (C) 2004 Elsevier Ltd. All rights reserved.