Study of structural and microstructural contributions to the optical and dielectric properties of NBBT binary relaxor composites substituted with trivalent and non-magnetic ions

Pb-free ceramic composites with tremendous energy storage performance have been optimized with alkaline -based additives. Herein, dual trivalent and nonmagnetic ions substituted binary [Na0.5Bi0.5-xLax]0.94Ba0.06Ti1-yAlyO3] relaxor ferroelectric ceramics have been designed and synthesized by conventional mixed oxide route reaction. The accumulated trivalent ions show the Morphotropic Phase Boundary (MPB) in all compositions. Moreover, the introduction of La3+ in different ratios reduces strain and increases grain size. The oxidation state of the prepared compound is tested by X-ray photoelectron spectroscopy. The lowest direct band gap was observed at an x = 0.02 ratio, which clearly indicates that this system is a photoactive material. Dielectric analysis denotes diffuse type relaxor behavior with the existence of grain and grain boundary resistance for all La3+ concentrations. The activation energy calculated from the Arrhenius law shows a low value with an increase in the ratio of rare earth (RE) ions, indicating the oxygen and Bi vacancies in the ceramic system.