Multifunctional Nd3+ substituted Na0.5Bi0.5TiO3 as lead-free ceramics with enhanced luminescence, ferroelectric and energy harvesting properties

Abstract

Herein, we present comprehensive investigations of the optical and electrical properties of Nd³⁺ substitution in sodium bismuth titanate ceramics (NBNT) with varying Nd³⁺ concentration. The room temperature photoluminescence (PL) emission for both unpoled and poled samples is observed to be a maximum for an Nd³⁺ substitution of 1 mol%. Upon poling, the PL intensity is observed to be quenched, consistent with the obtained XRD data, indicating an electric-field induced structural ordering towards higher symmetry, confirmed with the help of structural refinement. The evaluated ferroelectric to relaxor and antiferroelectric relaxor T_(F–R) was observed clearly from the poled dielectric–loss curve for the 1 mol% of Nd³⁺ substitution. Furthermore, the optimized NBNT exhibited a lower E_c and a higher off-resonance figure of merit (FOM_off) for energy harvesting by 12% and 30%, respectively, in comparison with un-doped NBT.