Influence of lightly Sm-substitution on crystal structure, magnetic and dielectric properties of BiFeO3 ceramics

Multiferroic Bi1−xSmxFeO3 (x = 0.00-0.05) ceramics were prepared by a conventional solid-state reaction method, and effects of Sm3+ ions on crystal structure, magnetic and dielectric properties were investigated. TGA-DSC studied the synthesis process of pure BiFeO3 sample and confirmed the synthesis temperature was about 825 °C. For all samples, they were rhombohedral distorted perovskite structure of R-3c space group. Lattice constants and particle sizes decreased based on the data of XRD and Rietveld refinement. Morphologies of the samples were determined with Scanning Electron Microscopy proving the grain to be shrinkage. With increasing of Sm3+ ions, saturation magnetization of Bi0.97Sm0.03FeO3 material at 5000 Oe was about 1.5 times larger than that of pure BiFeO3, while the coercivity increased from 87.3 Oe to 121.3 Oe. In a wide range frequency from 1 MHz to 1.6 GHz, dielectric constant kept a stable value. With Sm3+ increasing, dielectric constant increased from 27 to 46, while dielectric loss kept a low value.