Diffuse phase transition and ferroelectric study of (Ba, Bi)(Ti, Cr)O3 ceramics

Lead-free perovskite type (Ba0.94Bi0.06)(Ti0.94Cr0.06)O3 (BBTC) ceramics have been prepared by the conventional mixed oxide method. The XRD results showed that BBTC ceramics have single phase tetragonal symmetry with space group P4mm. Dielectric studies exhibited a diffuse phase transition characterized by a strong temperature and frequency dispersion of permittivity. The quantitative characterization based on empirical parameters (ΔTm, γ, ΔTrelax, and ΔTdif) confirmed its relaxor nature. The origin of relax ferroelectric behavior is caused by the polar nanoclusters, which were arose due to the heterovalent substitutions of Bi3+ and Cr3+ at Ba2+ and Ti4+ sites. The P–E loops obtained at the temperature quite above Tm supported the diffuse phase transition behavior of the samples.