Synthesis of textured Bi0.5(Na0.8K0.2)0.5TiO3-Ba0.844Ca0.156(Zr0.096Ti0.904)O3lead-free ceramics for improving their electrical and energy storage properties

In this study, lead-free (1-x)[Bi-0.5(Na0.8K0.2)(0.5)TiO3]-x[Ba0.844Ca0.156(Zr0.096Ti0.904)O-3] (BNKT-BCZT, wherex = 0.0, 0.025, 0.05, 0.075, and 0.1) ceramics were produced by tape-casting method to improve their relaxor behavior along with dielectric and energy-storage-density properties. A pure perovskite phase was found for all ceramic samples, which confirms the dissolution of BCZT into the lattice structure of the BNKT, resulting in a homogeneous solid solution. With the increase in the BCZT content, the phase structure of the ceramics transformed from the rhombohedralR3cto tetragonalP4bmstructure, as evidenced by the fact that a single (200)(R)peak splits into the (200)(T)/(002)(T)peaks. The simple phase diagram of BNKT-BCZT ceramics near the morphotropic phase boundary (MPB) indicates an interesting system with excellent ferroelectric and dielectric properties, and relaxation of the ferroelectric phase transition. Moreover, the experimental results demonstrated that the textured BNKT-BCZT ceramics exhibited excellent electrical and energy-storage-density properties with the following expected values atx = 0.05: maximum dielectric constant epsilon(max) = 7105, high remnant polarizationP(r) = 16 mu C/cm(2), low coercive fieldE(c) = 25 kV/cm, dielectric constant epsilon(r) = 1323, dielectric loss tan delta = 0.046, Lotgering factor (f) = 0.65, and energy storage density = 0.43 J/cm(3)at 50 kV/cm. Thus, the ceramic material has great potential in electrical-energy-storage applications.