Development of low band gap layered Bi6FeNiTi3O18 aurivillius phase ceramics for ferroelectric memory and cathode for lithium-oxygen batteries applications

Abstract

The layered multiferroic perovskite oxides are excellent functional materials for ferroelectric memory applications and also show application potential for cathode materials in lithium-oxygen battery due to high surface area, good stability, easy processing and low price. Synthesis of uniformly distributed layered perovskite oxides with low band gap, ionic-conducting and ferroelctric nature is still challenging. In this work, we have synthesized a new single-phase aurivillius phase Bi6FeNiTi3O18 ceramics by high-energy ball mill mechano-chemical reaction. The Rietveld refinement of XRD data reveals that the compound Bi6FeNiTi3O18 shows orthorhombic structure with space group P2/m and SEM images confirm the uniform layered morphology. Bi6FeNi Ti3O18 ceramic have shown very high Tc of 450 °C and typical relaxor behaviour. Impedance analysis reveals the effect of grains, grain boundaries and electrode on conductivity. Ferroelectric nature is confirmed by obtained P-E loop at room temperature. We also report much lower band gap (Eg = 1.87 eV) as compared to Bi6Fe2Ti3O18 (Eg = 3.2 eV) ceramics which is due to Ni 3d state formation below Fe 3d state. The present work provide new path to engineer the functional properties of perovskite oxides for memory and energy storage applications. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.