STRUCTURAL, DIELECTRIC, AND ENERGY STORAGE PROPERTIES OF Ba2+ DOPED LEAD-FREE NaNbO3-BASED CERAMICS

NaNbO3-based antiferroelectric ceramics have recently attracted significant attention due to their potential in energy storage applications. This study explores the effect of barium (Ba2⁺) doping on the dielectric and energy storage properties of 0.88NaNbO3-0.12Sr0.7Bi0.2TiO3 (0.88Na1-2xBaxNbO3-0.12Sr0.7Bi0.2TiO3, where x = 0.0-0.025) ceramics synthesized via the solid-state reaction method. The XRD results indicated that all samples possessed an orthorhombic structure. The transition temperature from the antiferroelectric P phase to R phase (TP-R) significantly increased from 141℃ at x = 0.0 to approximately 160°C for x ≥ 0.01. Additionally, the dielectric loss (tanδ) within the temperature range of 32°C to 130°C for the 100xBa ceramic exhibited a notable reduction, decreasing from 0.012 (x = 0.0) to 0.002 (x = 0.025). As the Ba2⁺ doping content increased, the remnant polarization significantly decreased, leading to a narrower P-E hysteresis loop with enhanced energy storage density and efficiency. Consequently, the x = 0.015 composition achieved a maximum recoverable energy storage density of 0.28 J/cm³ and an energy storage efficiency of 76% under an applied electric field of 125 kV/cm. These findings guide the development of NaNbO3-based antiferroelectric materials with enhanced energy storage.