Engineering 0.8BiFeO₃-0.2BaTiO₃ multiferroics with improved dielectric and magnetic properties via samarium doping

Samarium (Sm) modification is emerging as a powerful strategy to manipulate the electrical response of 0.8BiFeO₃-0.2BaTiO₃ (BFBT) multiferroic ceramics. In this work, Sm-doped BFBT (BFBT05Sm and BFBT01Sm) are successfully synthesized via the solid-state reaction technique. X-ray diffraction (XRD) analysis coupled with Rietveld refinement confirms the formation of a pure perovskite structure with rhombohedral symmetry (R3c space group) for all compositions, indicating the effective integration of Sm into the BFBT lattice. In particular, scanning electron microscopy (SEM) reveals a remarkable increase in grain size upon Sm doping, reaching 1.098 μm in BFBT01Sm compared to 0.192 μm in the BFBT sample. Further evidence for the R3c space group comes from Raman spectroscopy, which reveals identical vibrational modes in all samples. Most importantly, the Sm substitution significantly reduces the dielectric loss compared to BFBT. A comprehensive analysis of the Mössbauer spectral parameters reveals the influence of Sm doping on the magnetic interactions.