La and Cr induced structural modifications in BiFeO3 ceramics

Abstract

Bismuth ferrite (BiFeO₃) is a highly promising multiferroic material with extensive potential applications. This study investigates the impact of lanthanum (La) and chromium (Cr) doping on the structural properties of BiFeO₃ (BFO). Compositions BiFeO₃ (BFO), BiFe_0.95Cr_0.05O₃ (BFO1), Bi_0.95La_0.05Fe_0.95Cr_0.05O₃ (BFO2), and Bi_0.90La_0.10Fe_0.95Cr_0.05O₃ (BFO3) were synthesized using a solid-state reaction method at 800 ^oC. The incorporation of La and Cr into BFO aims to enhance its structural properties for potential applications in electronic and magnetic devices. Systematic analysis using X-ray diffraction (XRD), and Raman spectroscopy reveals significant changes in the lattice parameters, grain size, and phase stability of the doped ceramics. The rhombohedral structure of pure BFO, with the R3c space group, was confirmed as the primary phase through X-ray diffraction and Raman spectroscopy. The crystallite size obtained from both Scherrer’s and W-H method suggested that BFO1 sample has larger crystallite growth with low strain which favour the formation of dense and compact crystals. Rietveld refinement was done for BFO and BFO1 samples using FullProf suite to further analyses the crystal structure which also confirms the presence of R3c phase. The lattice constants increase for BFO1 and cell density decreases which infers the decrease in crystallinity for BFO1 sample. La doping results in an increase in the lattice parameters and an improvement in the crystallinity of the material, while Cr doping induces notable changes in the phase composition and microstructure. The combined effects of La and Cr doping lead to a more pronounced alteration in the structural characteristics, which are discussed in terms of the underlying mechanisms governing these modifications. These findings provide valuable insights into optimizing the synthesis and performance of BiFeO₃ ceramics for advanced technological applications.