Structural and electric properties of polycrystalline Bi1−xErxFeO3 ceramics

Polycrystalline Bi1−xErxFeO3 ceramics were synthesized by the solid state reaction method followed by rapid liquid phase sintering. The effects of Er substitution on the structure, morphology and electrical properties of the BiFeO3 multiferroic ceramics were investigated. X-ray diffraction and Raman studies reveal that the structure of BiFeO3 is changed from rhombohedral to orthorhombic in the Er concentration range of 0.10–0.15, and the impurity phases decrease both due to Er substitution. The X-ray photoelectron spectroscopy shows that Fe2+ could be suppressed by Er substitution. The SEM investigations suggest that the Er substitution could significantly reduce the grain sizes and increase the density of the samples. The leakage current is found to be decreased with increasing Er concentration. The dielectric and ferroelectric measurements show that dielectric constant, dielectric loss and ferroelectric properties are strongly dependent on the Er concentration. Er substitution can significantly improve the dielectric constant and remnant polarization, and decrease the dielectric loss by reducing the leakage current.