Quantitative description of the phase transition of Aurivillius oxides Sm modified BaBi4Ti4O15 ceramics

BaBi4Ti4O15+xwt.%Sm2O3 (x=0.00, 0.25, 0.50, 0.75) ceramics were prepared by the solid-state reaction method. The effect of samarium additives on the structural and electrical properties of BBT ceramic was investigated. XRD patterns indicate that all ceramics are an m=4 members of Aurivillius oxides and no secondary phases were detected. A broad dielectric peak in frequency dependent dielectric spectrum is observed during the phase transition of all the BBT ceramics. The modified Curie–Weiss law, Vogel–Fucher relationship and Lorentz-type law were used to describe the phase transition behavior. The relaxor behavior was described well by the modified Curie–Weiss law and Vogel–Fucher relation. The effect of samarium additives on the degree of relaxation and diffuseness of BBT ceramics was discussed.