Crystal structure, microstructure, energy band structure and electrical properties of MnO₂ doped (K,Na,Li)(Nb,Ta)O₃-(Bi,Na)TiO₃ ceramics

In this article, KNNLT-BNT lead-free ceramics were prepared by the solid solution method to regulate the grain size and electrical properties by Mn-doped. The doped concentrations were 0.3, 0.4, and 0.5%. The surface structure of the ceramic was characterized, and the Mn-doped can improve the ceramic compactness. The internal structure of the ceramic was analyzed, with the increase of Mn-doped concentration, the (101) peak shifted to a lower angle, and the lattice is distorted. Finally, the electrical properties of the ceramic were characterized by the optical band gap and dielectric constant. Analysis results show that when the Mn-doped concentration is 0.5%, the electrical performance is the best, the grain size follows a normal distribution, and the band gap width is the narrotest 2.693 eV.