Studies on structural, electrical and magnetic properties of Dy-doped BiFeO₃ thin films

Pure BiFeO₃ (BFO) and Bi_1−xDy_xFeO₃ (BD_xFO, x = 0.06–0.12) thin films were successfully deposited on fluorine-doped SnO₂ (FTO/glass) substrates by using a chemical solution deposition method. The microstructure, electric property and magnetic property of the Bi_1−xDy_xFeO₃ thin films were studied. And the conduction mechanism of the Bi_0.90Dy_0.10FeO₃ thin film was analyzed. The results show that a structural transition from the trigonal structure (R3c: H) to the trigonal structure (R3m: R) was observed in the Bi_1−xDy_xFeO₃ thin films. The dielectric property of the Bi_0.90Dy_0.10FeO₃ thin film has been improved, its dielectric constant at 1 kHz is 266. Furthermore, the Bi_0.90Dy_0.10FeO₃ thin film shows a relatively low leakage current density of 9.04 × 10⁻³ A/cm² at the applied electric field of 250 kV/cm. The interface-limited Fowler–Nordheim tunneling dominates the leakage current of the Bi_0.90Dy_0.10FeO₃ thin film at the higher applied electric field. The enhanced magnetic property was observed in the Bi_1−xDy_xFeO₃ thin films, which can be attributed to the structural transition and small grain sizes.