BiFeO_3薄膜的so-lgel制备及其铁电性能研究

Sol-gel preparation and electric properties of BiFeO_3 thin films

采用sol-gel方法在Pt(111)/Ti/SiO2/Si(100)衬底上制备出了(100)择优取向的BiFeO3薄膜.XRD研究表明,600～650℃退火的薄膜结晶较好.AFM形貌显示,650℃退火的薄膜中等轴状晶粒大小均匀(直径100～150nm),薄膜较为致密.电学性能测量结果表明,650℃退火、厚度为840nm的薄膜的2Pr值为2.8mC/cm2;在50kV/cm外加电场下,漏电流为2.7×10-5 A/cm2.电流-电压特性显示,在欧姆区之上,薄膜的主要导电机制为波尔-弗兰克尔发射导电.

BiFeO3 thin films of（100） preferential orientation were deposited through sol-gel process on（111）Pt/Ti/SiO2/（100）Si substrates.X-ray diffraction pattern indicates that good annealing temperature of films are 600~650 ℃.The dense thin film annealed at 650 ℃was composed of uniformed grains with equiaxed shape（100~150 nm in diameter）.The film（840 nm） annealed at 650 ℃ show very low remanent polarization（2Pr） of 2.8 mC/cm2 and large leakage current of 2.7×10-5 A/cm2 at 50 kV/cm.The main conduction mechanism of the thin films is Poole-Frankel emission conduction above the ohmic region.