Hydrothermal synthesis of Yb-doped BiFeO3 crystallites and their structural, magnetic and electrical properties

Abstract The influence of Yb doping on the structural, magnetic and electrical properties of bismuth ferrite (BiFeO3) was investigated. Well-crystallized BiFeO3 (BFO) and Yb-doped BiFeO3 powders (Bi1-xYbxFeO3: x = 0, 0.03, 0.05, 0.1) were successfully synthesized via a typical hydrothermal method. X-ray diffraction (XRD) revealed that powders have a distorted rhombohedral structure with a space group of R3c. Field emission scanning electron microscope (FESEM) studies indicated more or less cuboidal particles consisting of subparticles with different sizes. It was found that increase in Yb content retains the particle growth, therefore, reduces the size of these cuboidal particles. X-ray photoelectron spectroscopy (XPS), on the other hand, showed the presence of oxygen content in the lattice which was increased from 17.32% to 39.97% in doped BiFeO3 powders, indicating that doping with Yb reduces oxygen deficiencies in the lattice and ensures the formation of more M-O-M bonds. Vibrating sample magnetometer (VSM) measurements revealed that the highest saturation magnetization value was achieved as 0.09 emu/g for 3 at% Yb-doped BFO showing weak ferromagnetic behavior. Ferroelectric measurements were also conducted to find remanent polarization (Pr) value of samples. Among all samples, the highest Pr value, 0.37 μC/cm2, was attained for 3 at% Yb-doped BFO. From dielectric measurements, it was proved that incorporation of Yb into BiFeO3 perovskite structure enhances formation of M-O-M bonds, therefore, the highest dielectric constant and lowest dielectric loss were achieved in case of Bi0.9Yb0.1FeO3.