THE INSERTION EFFECT OF Bi-EXCESS LAYERS ON STOICHIOMETRIC BiFeO3 THIN FILMS PREPARED BY CHEMICAL SOLUTION DEPOSITION

The insertion effect of Bi-excess layers on stoichiometric BiFeO3 thin films prepared by chemical solution deposition is investigated. A stoichiometric BiFeO3 thin film with both the Bi-excess top and bottom surface layers shows improved crystallinity with the remanent polarization of 65 mu C/cm(2) at 80 K, which is larger than for BiFeO3 film prepared by the same process using stoichiometric solution. These results are attributed to the reduction of the imperfect crystal at the interface between the BiFeO3 film and electrode. By inserting Bi-excess layers, the saturated magnetization of all the films becomes smaller than that of the film using stoichiometric solution. Bi-excess surface layers at the top and bottom interfaces are an effective way to obtain good ferroelectric properties.