Ion modification for improvement of insulating and ferroelectric properties of BiFeO3 thin films fabricated by chemical solution deposition

Ion modification techniques for improving the insulating and ferroelectric properties of BiFeO3 (13170) thin films are reported. Rare-earth-substituted BFO films with chemical compositions of Bi1.00-xRExFe1.00O3 [RE = La and Nd] were fabricated on (111)Pt/TiO2/SiO2/(100)Si substrates using a chemical solution deposition technique. Well-saturated P-E curves were obtained for La3+ and Nd3+-substituted BFO films, while the curve of a nonsubstituted BFO film was distorted due to the leakage current. Remanent polarization (P-r) values measured at 10 K were respectively 44 and 51 mu C/cm(2), for La3+- and Nd3+-substituted BFO films, which are significantly superior to conventional Pb-free ferroelectrics.