Effects of Gd substitution on structure and ferroelectric properties of BiFeO3 thin films prepared using metal organic decomposition

BiFeO3 and Bi1-xGdxFeO3 (BGFO) (x=0.03, 0.05, 0.07, 0.10, and 0.15) thin films were deposited on Pt/Ti/SiO2/Si substrates using a metal organic decomposition process. X-ray diffraction results show that a gradual phase transition from rhombohedral to pseudotetragonal structure may occur in BGFO films with the increase of Gd content. Due to the lower leakage currents resulting from the smaller grain sizes and smoother surfaces, well saturated P-E hysteresis loops, which show weak dependence of frequency in the range of 3-50 kHz, can be observed in all BGFO films at room temperature. The remanent polarization for BGFO(x=0.03) film is about 79 mu C/cm(2). In addition, no evident fatigue can be observed after 10(9) switching cycles. (c) 2007 American Institute of Physics.