Preparation and properties of rare earth (Eu, Tb, Ho) and transition metal (Co) co-doped BiFeO3 thin films

Abstract

Ferroelectric (Bi0.9 RE 0.1)(Fe0.975Co0.025)O3-δ (RE = Eu, Tb and Ho) thin films were prepared on Pt(111)/Ti/SiO2/Si(100) substrates via a chemical solution deposition method. All thin films were crystallized in a distorted rhombohedral perovskite structure confirmed by using an X-ray diffraction and a Raman scattering analyses. Compared to the pure BiFeO3 thin film, improved electrical and ferroelectric properties were observed for the co-doped thin films. Among the thin films, the lowest leakage current density of 4.28 × 10−5 A/cm2 was measured at an applied electric field of 100 kV/cm for the (Bi0.9Ho0.1)(Fe0.975Co0.025)O3-δ thin film. This value is approximately three orders lower than that of the pure BFO thin film. Furthermore, a large remnant polarization (2P r) of 60.2 μC/cm2 and a low coercive field (2E c ) of 561 kV/cm at 980 kV/cm were observed from the (Bi0.9Ho0.1)(Fe0.975Co0.025)O3-δ thin film.