Microstructure and Physical Properties of (Eu, Ni) Co-Doped BiFeO3 Materials

Abstract

BiFeO3 (BFO) and Bi1-x Eu x Fe0.975Ni0.025O3 (x = 0, 0.025, 0.05, 0.075, 0.10) materials were synthesized by sol-gel method. The structural, optical, ferromagnetic, and ferroelectric properties of all samples were systematically investigated using different techniques. Analysis results of XRD showed that all samples were crystallized in the rhombohedral structure with R 3C space group. The crystal lattice parameters were a = 5.563 Å, c = 13.833 Å and crystal size is L XRD = 519 Å for BiFeO3 materials whereas the a, c, and L XRD of (Eu, Ni) co-doped samples decreased with Eu concentration. Raman scattering spectra were used for confirming the substitution of Eu3+ ions into Bi-sites. Fluorescence spectra showed the enhancement of characteristic emission peaks with Eu concentration. The BFO exhibited weak ferroelectric behavior with a maximum polarization of P s = 12.698 μC cm−2, remnant polarization of P r = 7.351 μC cm−2. Ferroelectric properties of the (Eu, Ni) co-doped samples were significantly enhanced. The BFO material exhibited a weak ferromagnetic behavior with saturation magnetization of M s = 0.036 emu g−1, remnant magnetization of M r = 0.004 emu g−1. The ferromagnetic properties of sample were also improved with presence of (Eu, Ni) dopants. The origin of the improvement in ferromagnetism, ferroelectricity, and fluorescence were also thoroughly discussed.