Investigation of diversified properties in trivalent La doped Bi1−xLaxFeO3 compounds

• Published in: Journal of materials science. Materials in electronics 2024-05, Vol.35 (15), p.1012, Article 1012
• Main Authors: Jadav, G. D., Kanjariya, P. V., Bhalodia, J. A.
• Format: Article
• Language: English
• Subjects: Bismuth ferrite; Characterization and Evaluation of Materials; Chemistry and Materials Science; Diffraction patterns; Doping; Electric fields; Ferroelasticity; Ferroelectric materials; Ferroelectricity; Ferromagnetic materials; Grain size; Hexagonal lattice; Iron constituents; Materials Science; Metal oxides; Multiferroic materials; Optical and Electronic Materials; Perovskite structure; Perovskites; Room temperature; Software; Spectrum analysis; Substitution reactions; Unit cell
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-024-12661-x

Multiferroic materials are characterized by the coexistence of two or more properties of ferroelectricity, ferromagnetism and ferroelasticity. The coexistence of at least two ferroic forms of ordering leads to additional interactions. A typical example is that of magnetoelectric multiferroic materials, in which an applied electric field can tune the ferromagnetic properties of the materials, and vice versa. To investigate various properties by La doping at Bi—site in BiFeO 3 (BFO), we have successfully synthesized Bi 1− x La x FeO 3 ( x  = 0.04, 0.08, 0.12, 0.16 and 0.20) compounds by the solid state reaction method. TGA analysis suggests that the reaction occurred in two stages and plateau region was observed at the temperature range of 800 to 960 °C. FTIR spectroscopy confirmed the formation of metal oxide bonds (Fe–O and Bi/La–O) and FeO 6 octahedra in all the samples. The X-ray diffraction patterns were indexed in the hexagonal lattice for rhombohedral perovskite structure. Rietveld refinement of the La doped BFO samples were done using FullProf software. The unit cell structures were drawn using VESTA software, in which it was found that Bi/La atoms are not present exactly in the middle of two consecutive FeO 6 octahedra showing the off-center displacement of Bi/La. The substitution of trivalent La at Bi—site in BiFeO 3 does not lead to any structural transition up to the end member of the series. SEM analysis shows that said La substitution in BiFeO 3 considerably modifies the grain size of the material. The EDAX spectra confirmed the presence of all the constituent elements i.e., Bi, La, Fe, and O in each composition, whereas the EDAX mapping analysis confirms the successful La doping in BFO via increment in its spectral density with increasing doping concentration. P-E loops of these samples exhibit leaky behavior indicating poor ferroelectric nature. Compare to all remaining samples, the ferroelectric properties were found effectively enhanced for 12% La doped BFO sample. While at lower La-concentration, the structure of BFO is distorted and produces off-centering of Bi-ion along c-axis resulting in large space-charge polarization which gives rise to the ferroelectric behavior that reduces as the La-concentration increases. La doped BiFeO 3 samples show ferromagnetic behaviour at room temperature, which is different from the linear M–H relationship reported for undoped BiFeO 3 sample.