Investigation of the properties of BiFeO3/intermediate-layer structures fabricated by magnetron sputtering

Abstract

The properties of BiFeO3/intermediate layer/substrate structures fabricated by radio-frequency magnetron sputtering at low temperatures (450°C) and by deposition on substrates and intermediate layers between the substrate and the BiFeO3 film have been investigated. In the structures, glass substrates or commercial Pt/Ti/SiO2/Si(001) substrates have been used, and intermediate layers have been prepared from L10 FePt or Pt films. Intermediate layers of Pt and L10 FePt have the (111) and (001) textures, respectively, induced by rapid thermal annealing. It has been revealed that the deposition on the commercial substrates leads to the formation of BiFeO3 isotropic films that have a large surface roughness and consist of grains ∼200 nm in size with the BiFeO3 perovskite structure. In the case of the deposition of a BiFeO3 film on a Pt(111) intermediate layer, the BiFeO3 phase is suppressed. The deposition on an intermediate layer of the L10 FePt film with the (001) texture results in the formation of a single-phase BiFeO3 film with the (001) texture and the perovskite structure, which (as compared to the BiFeO3 films grown on the commercial substrate) has a less pronounced roughness, smaller grain sizes, and significantly better ferroelectric properties.