The structural and multiferroic properties of Bi(1−x)Ce x Fe(1−x)(Mg0.5Ti0.5) x O3 thin films

Abstract

Bi(1−x)Ce x Fe(1−x)(Mg0.5Ti0.5) x O3 (x = 0, 0.05, 0.10, 0.20, 0.25) thin films were synthesized by a sol–gel method. The structural, electrical and magnetic properties of Bi(1−x)Ce x Fe(1−x)(Mg0.5Ti0.5) x O3 (x = 0, 0.05, 0.10, 0.20, 0.25) thin films have been investigated. BiFeO3 thin film possessed a perovskite-type rhombohedral structure with space group R3c, and the average grain size decreased as the concentration of Ce, Mg and Ti co-doping increased. The leakage current densities of BiFeO3 co-doping with Ce, Mg and Ti ions exhibited a significant reduction compared with that of BiFeO3 thin film. Compared with the leakage current density of BiFeO3 thin film (4.19 × 10−4 A/cm2), the leakage current density of Bi0.80Ce0.20Fe0.80Mg0.10Ti0.10O3 thin film was reduced by about four orders of magnitude (1.05 × 10−8 A/cm2) under the electric field of 300 kV/cm. Well-defined ferroelectric loops were obtained and the polarization increased with the increase of Ce, Ti and Mg co-doping. The remanent polarization of Bi0.80Ce0.20Fe0.80Mg0.10Ti0.10O3 thin film (2P r ~34.9 μC/cm2) was approximately four times larger than that of pure BiFeO3 (2P r ~7.8 μC/cm2) under the applied field of 300 kV/cm. The magnetization under 10 kOe magnetic field of Bi(1−x)Ce x Fe(1−x)(Mg0.5Ti0.5) x O3 thin films increased with the increasing concentration of Ce, Mg and Ti co-doping. The improvement of magnetic behaviors for BiFeO3 co-doping with Ce, Mg and Ti ions thin films were observed significantly, cooperating with the enhanced ferroelectricity which indicated that BiFeO3 co-doping with Ce, Mg and Ti ions thin films will be the promising materials in the application to magnetoelectric devices.