Smart materials: the functional properties of ceramic/polymer composites and their relation to sol-gel powder preparation

摘要

Ferroelectric powders of lead titanate (PT) and calcium modified lead titanate (PTCa) were prepared by the sol-gel process. The gels were dried and heat treated near 500°C (crystallisation temperature) using various procedures. The final ceramic powders were mixed with a polymer, in this case P(VDF-TrFE), 50 % in volume and films of about 100 μm were obtained by hot pressing. The DC conductivity of the composite films at high fields (>10 MV/m) seems to be dependent on the crystallisation process to which the sample was submited. The electroactive properties of the composites were studied.