Structural and Electrical Properties of Perovskite (Na0.5Bi0.5)0.99Sm0.01Ti0.9975O3 and Bismuth Layered Sr0.8Bi2.15Ta2O9 Ferroelectric Composites Synthesized by a Microwave Processing Technique

(1-x)(Na0.5Bi0.5)(0.99)Sm0.01Ti0.9975O3-xSr(0.8)Bi(2.15)Ta(2)O(9)/(1-x)NBST-xSBT (where x = 0, 0.04, 0.08, 0.12, and 0.16) composites, comprising perovskite NBST and bismuth-layered SBT phases, were prepared by a solid-state reaction-assisted microwave processing technique. The structure of the composites was investigated by x-ray diffraction, which confirmed the coexistence of both phases in the synthesized composites. The microstructural study by field emission electron scanning electron microscopy showed a dense and inhomogeneous distribution of grains, which increased with the increase in SBT content. Detailed dielectric studies of the composite ceramics as a function of frequency (1 kHz to 1 MHz) and temperature showed a broadening of the permittivity peak near the transition temperature. A decrease in the transition temperature with an increase in SBT content was attributed to increased inhomogeneity and internal stress. Ferroelectric study revealed that both the coercive field and remnant polarization decreased with an increase in SBT content. The leakage current density of the composite system decreased with the increase in SBT content in the composites. A reduction in fatigue behavior was observed with the incorporation of SBT in the composites. Among the studied composites, the x = 0.08 system showed potential for use in ferroelectric nonvolatile random-access memory applications. [GRAPHICS] .