Cu2+ and W6+ co-doped Na0.5Bi0.5TiO3 solid solution: an effective approach to inhibit oxygen vacancy generation and suppress oxygen ion conduction

Thanks to its outstanding features, the Na0.5Bi0.5TiO3 is a promising as a dielectric material for various advanced electronic devices. However, its high oxygen ionic conductivity and wide band-gap energy pose limitations on its suitability for commercial applications. In this work, an approach to inhibit oxygen vacancy generation and suppress oxygen ion conduction is investigated through the B-site donor and acceptor doping strategy. This study aims to investigate the morphological, structural, compositional, dielectric, electric, and optical properties of 0.99NBT-0.01BCW and 0.985NBT-0.015BCW perovskite ceramics. The research also explores the impact of Cu2+ and W6+ substitution on the perovskite structure and its potential applications. Morphological analysis revealed well-defined grains with cubic shapes, influenced by Cu2+ and W6+ incorporation. Structural analysis confirmed a rhombohedral lattice with R3c space group. Dielectric analysis showed ferroelectric to antiferroelectric and antiferroelectric to paraelectric phase transitions, with emphasis on relaxor behavior influenced by BCW doping. Electric analysis demonstrated a semiconductor behavior with activation energies, suggesting inhibited conduction loss at high temperatures due to BCW doping. Optical analysis revealed direct bandgap energies suitable for applications in optoelectronics and photonics. These findings suggest that doping with Cu2+ and W6+ restrains conduction losses at elevated temperatures, potentially serving as the primary mechanism for suppressing the high-temperature dielectric loss in NBT-based ceramics. They highlight the potential of these perovskite ceramics in applications such as capacitors, sensors, and optoelectronic devices.