Structural, magnetic, and optical properties of Pr and Zr codoped BiFeO_3 multiferroic ceramics

摘要

Single-phase (Bi_(1-x)Pr_x)(Fe_(1-x)Zr_x)O_3 ceramics with x = 0.03, 0.06, 0.10 (named BPFZ-3, BPFZ-6, and BPFZ-10, respectively) were synthesized by solid state reaction method. X-ray diffraction suggested the pure phase formation with distorted rhombohedral structure in all samples. Raman spectroscopy also confirmed the rhombohedrally distorted perovskite structure with R3c symmetry. The x-ray photoelectron spectroscopy measurements showed the absence of Fe~(2+) ions indicating the suppression of oxygen vacancies due to Pr and Zr codoping. Room temperature magnetic hysteresis loops revealed that the spontaneous magnetization increases due to structural distortion and partial destruction of spiral spin structure caused by the codoping in BiFeO_3 ceramics. The maximum remnant magnetization of 0.1234 emu/g was observed for BPFZ-6 sample. Optical studies showed absorption of light in the visible region, with a red shift in energy band gap with increasing concentration of Pr and Zr in BiFeO_3 ceramics. The broad absorption bands due to the overlapping of Fe-O and Bi-O groups' vibrations were found in FTIR. Frequency independent dielectric constant and low dielectric loss at room temperature were observed for all samples.