Characteristics of Undoped and Mn-Doped BiFeO3 Films Formed on Pt and SrRuO3/Pt Electrodes by Radio-Frequency Sputtering

Pure BiFeO3 (BFO) and Mn-doped BiFeO3 (BFMO) films were deposited at 550 degrees C on Pt(111) and SrRuO3(SRO)/Pt(111) bottom electrodes using radio-frequency (RF) sputtering. Mn doping of 5 at. % into BFO films was effective in reducing leakage current density at a high electric field. In polarization versus electric field (P-E) measurement at 100 kHz, square hysteresis loops were obtained at room temperature in both BFO and BFMO films on Pt and SRO/Pt electrodes. In the BFMO films, the frequency dependence of the remanent polarization was not pronounced, even when the measurement frequency was decreased to 5 kHz. In the BFO film, on the other hand, no accurate hysteresis loops could be measured at a frequency below 10 kHz, because of the large leakage current. (C) 2009 The Japan Society of Applied Physics