An investigation on cubic and monoclinic phase coexistence in sol-gel derived LaFeO3-Na0.5Bi0.5TiO3 ceramics

LaFeO3 modified Sodium Bismuth Titanate (NBT) with composition (LaFeO3)(x)-(Na0.5Bi0.5TiO3)(1-x) where x = 0, 0.01, 0.03 and 0.05 (abbreviated as LFNBT0, LFNBT1, LFNBT3 and LFNBT5) have been synthesized via sol-gel method. The Rietveld refinement of room temperature XRD data certified the phase purity and the coexistence of a cubic (Pm (3) over barm) and a monoclinic phase (Cc). An increase in molar % of monoclinic phase takes from 1.66% to 16.53% with increasing LaFeO3 content. The Raman spectra cross verifies the XRD results and SEM micrographs reveal the dense microstructure and well-packed distribution of grains. Almost lossy P-E loops have been observed for all the samples and the ferroelectric behavior reduces with doping. LFNBT1 sample is found to be paramagnetic where as weak ferromagnetic character is observed in LFNBT3 and LFNBT5. The overlapped ZFC and FC magnetization curves in both LFNBT3 and LFNBT5 assured the absence of any kind of magnetic ordering. (C) 2020 Published by Elsevier B.V.

Automated summary

LaFeO3 modified Sodium Bismuth Titanate (NBT) with varying LaFeO3 content were successfully synthesized via sol-gel method. The XRD and Raman spectra confirmed the phase purity and microstructure of the samples. Ferroelectric behavior decreased with doping, with some samples showing paramagnetic or weak ferromagnetic characteristics. The absence of magnetic ordering was confirmed in certain samples through ZFC and FC magnetization curves.