Aurivillius type ferroelectric ceramics, SrBi2-xLaxNb2O9 were synthesized through the molten salt method to clarify how La3+ substitution influences both the crystal framework and the ferroelectric response. XRD data revealed the formation of a single orthorhombic A21am phase for all compositions which was further verified through Le Bail refinement. FTIR further supported the stability of Nb-O linkages. Microstructural examination by SEM indicated that increasing La3+ content suppressed grain growth. Dielectric measurements showed a systematic lowering of the ferroelectric transition temperature, consistent with enhanced orthorhombicity and the reduced stereoactivity of the Bi3+ 6s2 lone pair. Polarization hysteresis loops demonstrated that La3+ modification improved room temperature polarization behavior, attributed to reduced dielectric loss and more mobile domain walls. These results establish a clear link between structural distortion and ferroelectric response in La3+ modified SrBi2Nb2O9, underscoring the potential of this system as a model compound for understanding structure property relationships in layered ferroelectrics.
Zulhadjri et al. (Thu,) studied this question.