Structural, Optical, Ferroelectric and Ferromagnetic Properties of Bi1−xGdxFeO3 Materials

Bi 1− x Gd x FeO 3 (BGFO) ( x = 0.00 ÷ 0.15) materials were prepared by a sol-gel method. The effect of Gd doping on the structural, ferromagnetic, and ferroelectric properties of BiFeO 3 (BFO) were analyzed using x-ray diffraction, Raman scattering, energy-dispersive x-ray spectroscopy, ferroelectric hysteresis loop and magnetic hysteresis loop measurements. All samples showed a rhombohedral structure of the perovskite type. The a and c lattice parameters decreased with Gd content, obeying Vegard’s law, from 5.583 to 5.511 Å, and from 13.869 Å to 13.741 Å, respectively. The optical band gap ( E g ) also decreased with Gd content, from 2.02 to 1.60 eV at x = 0.00 to x = 0.15, respectively. The ferroelectric and ferromagnetic properties of the BGFO materials were enhanced compared with those of the pure BFO material. Maximum saturation polarization ( P s ) and saturation magnetization ( M s ) values of 6.88 μ C/cm 2 and 0.386 emu/g were obtained. We found that the optimum Gd doping content to enhance multiferroic properties of BFO material is in range from x = 0.10 to x = 0.125. The origin of ferromagnetic and ferroelectric properties of BGFO materials were also discussed.