Comparative study of structural and electrical properties of Pr and Ce doped BiFeO3 ceramics synthesized by auto-combustion method

Abstract Polycrystalline Bi 1−x Pr(Ce) x FeO 3 ceramics ( x  = 0, 0.03, 0.05 and 0.10) were prepared by auto-combustion method using urea as a fuel. The influence of Pr(Ce) doping on structural, vibrational, morphological, dielectric and ferroelectric properties of BiFeO 3 polycrystalline ceramics was investigated. From X-ray diffraction (XRD) and scanning electron microscopy measurements it was observed that Pr(Ce) doping generated a reduction of the crystallite (grain) size of BiFeO 3 and contraction of the rhombohedral cell due to the increased compressive strain. The changes seen in the XRD and Raman spectra of 10% Pr(Ce)-doped samples, pointed to a probable appearance of orthorhombic (pseudotetragonal) crystal structure. The pristine BiFeO 3 exhibited rounded shape, non-saturated ferroelectric hysteresis loop. The dielectric constant and dielectric loss have shown strong dispersion at lower frequencies, typical for conductive BiFeO 3 . Dielectric and ferroelectric properties at room temperature were improved with Pr doping. Concerning the Ce-doped samples, only the 3% Ce-doped sample exhibited a better shaped hysteresis loop and improved dielectric properties compared to the pristine BiFeO 3 . With further increase of Ce content the ferroelectric properties degraded.