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

Abstract

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 (Pm3̅m) 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.