7Kohlstedt H,Pertsev N A,Contreras J R,et al.Theoretical current-voltage characteristics of ferroelectric tunnel junctions[J] ,Phys Rev B,2005,72:125341.
8Kohlstedt H,Pertsev N A.Size effects on polarization in epitaxial ferroelectric films and the concept of ferroelectric tunnel junctions including first results[J].Mater Res Soc Symp Proc,2002,688:65.
9Zembilgotov A G,Pertsev N A,Kohlstedt H,et al.Ultrathin epitaxial ferroelectric films grown on compressive sub-strates:Competition between the surface and strain effects[J].J Appl Phys,2002,91(4):2247.
10Na S,Alexie M K,Andrew M R.Ferroelectricity in ultra-thin perovskite films[J].Phys Rev B,2005,72(2):020101.
