Optimizing energy storage and pyroelectric characteristics through A-site disorder in (Bi0.5Na0.5)TiO3 – based ceramics

Dielectric materials are widely used in high-energy storage devices as an essential component of electronic capacitors.
While a high pyroelectric coefficient caused by high remnant polarization (Pr) can restrict their superior and wider energy
storage performance. Here, (0.8-x)(Na0.5Bi0.5)TiO3-0.2SrTiO3-xBaTiO3 (NBSTBx) (x = 0.0, 0.05, 0.1, and 0.15) ceramic
materials prepared by the solid solution method were targeted to undergo the idea of present research. The crystal lattice
symmetry increased as configurational entropy (ΔS) increased, resulting in the disrupting of ferroelectricity long-range
order of NBT-ST ceramic. Two exclusive dielectric anomalies accompanying large-temperature nanoregions (PNRs) in the
ergodic relaxor (ER) case and short-temperature PNRs in the nonergodic relaxor (NR) case are recognized at x < 0.1. The
highest activation energy (Ea = 0.098 eV) was achieved at 0.1 of BT, which denotes low coupling between polar clusters,
resulting in intriguing to establish ordered polarized zones with large polarization. The pyroelectric parameter (PE) was
evaluated by an approximately numeric technique through differentiating remnant polarization Pr as a function of temperature.
The suppression of PE was achieved at NBSTB0.1 sample close to the phase transition temperature. However,
high figure of merit coefficient (FOM = 7.9 × 10− 9 C.cm− 2.°C− 1) was achieved at T = 180 °C indicating the material is suitable
for pyroelectric applications at high T. The present work shows a good paradigm for enhancing the energy storage
performance of NBT ceramics via suppression of pyroelectric characteristics to converge the demanding requirements of
energy storage applications.