Influence of Tb doping on structure and multiferroic properties of BiFeO3 films prepared by pulsed laser deposition

Tb-doped bismuth ferrite (Bi1−xTbxFeO3, 0 ≤ x ≤ 0.15) films were prepared on Pt(1 1 1)/Ti/SiO2/Si substrates using a pulsed laser deposition method, so as to modify the multiferroic properties of BiFeO3 films by appropriate Tb doping. The effects of Tb concentration on the crystallographic structure, surface morphology as well as the dielectric, ferroelectric and ferromagnetic properties of the films were investigated. Single-phased Bi1−xTbxFeO3 films were obtained at x = 0.05-0.15, and the structural transition from tetragonal or orthorhombic to rhombohedral occurred as increasing Tb concentration, with the decreasing in grain size. The addition of Tb improved the ferromagnetic property of BiFeO3 films although the ferroelectric polarization was slightly degraded, showing obvious magnetic hysteresis loops and typical antiferromagnetic characters. The coexistence of ferroelectric property and ferromagnetic property was realized at room temperature in the Bi1−xTbxFeO3 films by appropriate Tb doping.