Tio Putra Wendari, Muhammad Ali Akbar, Alfir Rizki, Zulhadjri, Yulia Eka Putri, Andon Insani, Nandang Mufti
In recent years, dielectric capacitors based on ferroelectric compounds have attracted great interest as energy storage materials. Solid solutions based on Na0.5Bi0.5TiO3 (NBT-based) exhibit relatively high polarization and are considered promising dielectric energy storage materials. We have prepared (Na0.5Bi0.5)1-xCaxTiO3 ceramics (x = 0, 0.125, and 0.25) by the molten salt method and investigated their structures, dielectric properties, and energy storage properties. The structural refinement using the Rietveld method reveals overall structural distortions in all samples, including A-site shifting, TiO6 octahedral distortion, and Ti–O–Ti tilting, which result in a non-centrosymmetric structure responsible for the observed ferroelectric properties. With the increase in Ca2+ content, the grain size and maximum dielectric constant gradually decrease. Furthermore, the peak of the maximum dielectric constant (Tm) shifts to lower temperatures, indicating the enhancement of polarization dynamics. As a result, optimum properties are identified in (Na0.5Bi0.5)0.75Ca0.25TiO3 (x = 0.25) with a recoverable energy density of 9.938 mJ/cm3 and an outstanding energy efficiency of 80.8 % at a low electric field of 25 kV/cm. A ferroelectric polarization measurement at 150–190 °C for samples with x = 0.25 showed an increase in the values of Pm, Wrec, and ƞ is stable at high temperatures. This indicates that the energy storage material has good thermal stability at high temperatures. © 2025 Elsevier Inc.
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Andalas, Padang, 25163, Indonesia; Nuclear Energy Research Organization, National Research, and Innovation Agency, Tangerang Selatan, 15314, Indonesia; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang 5, Malang, 65145, Indonesia
