Phase transition and optical properties of samarium-doped BiFeO3 nanoparticles

Multiferroics are the materials having ferroelectric and magnetic properties simultaneously and can be tuned by controlling electric and magnetic field for the desired applications. Pure and samarium-doped bismuth ferrite nanoparticles Bi1−xSmxFeO3 (BSFO x = 0, 0.05, 0.10, 0.15, 0.20) with varied doping concentrations have been synthesized using sol–gel technique. The effect of doping on structural, morphological, elemental composition and optical properties were analyzed using various characterization techniques. X-ray diffraction (XRD) analysis of Bi1−xSmxFeO3 samples show the compressive lattice distortion and structural phase transformation from rhombohedral to orthorhombic phase. The Rietveld refinement shows that the crystalline structure of pristine BiFeO3 (BFO) is typical rhombohedral structure with R3c space group. Scanning electron micrograph (SEM) reveals that with increasing Sm concentration the grain size decreases up to ~ 30 nm. XRD and SEM analysis confirmed the synthesized samples having pure phase formation and nanocrystalline nature. Ultraviolet–Visible (UV–Vis) spectra of the samples show that the enhanced visible light absorption would be a promising material for photocatalytic application. The findings of X-ray photoelectron spectroscopy (XPS) verify the effective Sm doping in BFO samples.