IMF2017

Barium titanate (BaTiO₃) BT-based ceramics are of interest as the promising smart materials in commercial electrical components. However, they suffer from high sintering temperature requirement, low dielectric constant and high dielectric loss, causing a limitation for their practical utilizations. Thus, several solutions have been proposed to overcome these limitations including an approach of reinforcing the ferroelectric matrix phase with high electrical conducting phases. In this work, small amount of gold nanoparticles reinforced BT composites were developed by employing a solid-state sintering techniques without any binders. Apart from their environmental friendly, gold nanoparticles are thought to be reasonable candidate used for shortening the electrode distance in the nanometal/BT ceramics. These nanocomposites are expected to synergistically combine the properties of both the ferroelectric BT and the conductive gold nanoparticle, which could exhibit dielectric properties that are better than those of the monolithic BT ceramics. By employing a combination of several characterization techniques, the obtained results indicate that using different sintering temperature or gold nanoparticle amounts to produce the composites greatly affect the perovskite phase formation, densification, microstructure and dielectric properties of the materials. This work also addresses the domain evolution processes in BT-based ceramics containing various amounts of gold nanoparticles (AuNPs) as an additive by using piezoresponse force microscopy (PFM). The obtained PFM images of the ceramics revealing the change of one spontaneously polarized state to another under various applied direct current voltage are discussed in terms of their domain topology, PFM phase shift and PFM amplitude.