Dielectric Relaxation of La ³⁺ ‐Modified Bi ₃ TiNbO ₉ Aurivillius Phase Ceramics

Abstract

Single Aurivillius phase Bi 3− x La x TiNbO 9 (LBTN‐ x , x =0.00, 0.50, 0.75, and 1.00) ceramics were prepared by the conventional solid‐state reaction method. When x ≤0.50, the ceramics are normal ferroelectrics, while LBTN‐0.75 and LBTN‐1.00 showed typical relaxor behavior, which could probably be attributed to the disordering induced by the La 3+ partly substituting for Bi 3+ in Bi 2 O 2 layers. The dielectric relaxation of LBTN‐0.75 and LBTN‐1.00 were fitted using the Vögel–Fulcher relationship, and the results suggest that both of them are analogous to a spin glass with thermally activated polarization fluctuations above a freezing temperature.