Effect of Na+ Substitution on the Phase, Microstructure, Electrical and Energy Storage Properties of BSBZNT Ceramics Prepared by the Solid-State Combustion Technique

(Ba0.704Sr0.176Bi0.12)1-xZn0.08Nb0.04Ti0.88O3-Nax (BSBZNT-xNa) ceramics with x = 0, 0.01, 0.03 and 0.05 mol%, were prepared by the solid-state combustion technique. The samples were calcined and sintered at 950 °C and 1375 °C, respectively, for 2 h. The phase, microstructure, dielectric, ferroelectric and energy storage properties were investigated. The X-ray diffraction patterns of the BSBZNT-xNa powders showed a perovskite phase for all samples. When x increased from 0-0.03, the average particle size increased from 380 to 480 nm, then decreased to 420 nm. All sintered samples showed the coexistence of the orthorhombic and cubic phases. The average grain size was in the range of 2.03 to 1.39 µm. The BSBZNT-0.01Na ceramic exhibited the highest dielectric properties at room temperature (ɛr = 902, tanδ = 0.10), the lowest remanent polarization (P r = 0.10 µC/cm²), coercive field (E c = 0.43 kV/cm), and the highest energy storage efficiency (η ∼ 94.70%) measured under an electric field of 70 kV/cm.