Abstract
Dielectric response of poly(vinyl chloride), (PVC), loaded with different amount of Ba0.3Na0.7Ti0.3Nb0.7O3 (BNTN) ceramic powders was investigated in frequency range 100 Hz–1 MHz and temperature range 100–450 K. Ceramic solid solution of barium titanate and sodium niobate with composition Ba0.3Na0.7Ti0.3Nb0.7O3 was obtained from BaCO3, TiO2, Na2CO3 and Nb2O5 by conventional method. Powders were prepared by grinding of ceramics. The obtained ceramics, used to produce BNTN–PVC composites, are characterized by the relaxor behaviour with a broad peak of dielectric permittivity ε′ at T m ≈ 230 K. The microstructure of the powders was observed and the grain size was estimated using scanning electron microscope Hitachi S-4700. The EDS analysis confirms the qualitative and quantitative chemical composition of powders and ceramics. The BNTN–PVC composite samples of 0-3 connectivity were prepared from ceramic and polymer powders by hot-pressing method. The dielectric response of the composites displays features originated from the PVC polymer modified by those of BNTN ceramics. The relaxation time of the α-process of PVC obeys the Vogel–Fulcher law and decreases with increasing volume fraction of the ceramics.