Dielectric and ferroelectric properties of SrBi4Ti4O15–Sr2Bi4Ti5O18 composite ceramics

The bismuth layered structure ferroelectric ceramic composite between SrBi4Ti4O15 and Sr2Bi4Ti5O18 was synthesized through modified oxalate route. Phase formation behaviour of each compound in the composite was studied. The XRD analysis revealed the growth of two separate phases without forming any periodic intergrowth structure between them. The Rietveld structure refinement disclosed an increase in the lattice parameter of both phases. The densification behaviour of the composite powder was investigated using dilatometer. There was a preferential orientation in growth of plate like grains during sintering. The composite ceramic showed an additional dielectric anomaly peak in between the peaks for SrBi4Ti4O15 and Sr2Bi4Ti5O18 phases. The ferroelectric hysteresis property of the composite ceramics represented an average behaviour of two phases.