Characterization and Analysis of (1-x) Ba0.96Sr0.04Zr0.1Ti0.9O3–xNaNbO3: A Study on Structural, Dielectric and Energy Storage Behaviour

Due to their environmental friendliness, high power density, and quick charge–discharge properties, lead-free ceramic capacitors are having high demand in various electronic systems, pulse power supply systems, automobiles, distributed power systems etc. Nevertheless, the concurrent higher recoverable energy storage density (Wrec) and efficiency (η) are still difficult to obtain and must be researched. The energy storage properties can be increased by lowering the residual polarisation and raising the breakdown strength to produce a dielectric capacitor with a high Wrec and η. Due to its antiferroelectric and ferroelectric properties, lead-free ceramics based on NaNbO3 have much potential for energy storage and piezoelectric devices. Pure NaNbO3, however, typically exhibits lossy hysteresis loops due to the metastable antiferroelectric phase at ambient temperature. In this work, NaNbO3(NN) was introduced in Ba0.96Sr0.04Zr0.1Ti0.9O3(BSZT) to modulate the phase structure, dielectric and energy storage properties. Structural study confirms the formation of a monoclinic phase in NN, while for the (1-x) BSZT-xNN, the formation of a tetragonal phase has been observed. The microstructural study of the ceramic composite reveals the formation of dense microstructure with a decrease in grain size with increased NN content. The dielectric study reveals the diffuse phase transition (DPT) behaviour of the material around the curie point. With the increase in NN content dielectric constant was found to decrease with a dielectric loss (tan δ) value ≤ 0.20 for all compositions. From the ferroelectric study, an optimal recoverable energy density (Wrec) = 0.16 J/cm3, efficiency (η) = 84.2% has been achieved at 40 kV/cm for x = 0.06 composition.