Comparative studies on ferroelectric properties of mn-substituted BiFeO3 thin films deposited on Ir and Pt electrodes

Ferroelectric properties and fatigue endurance of 5% Mn-substituted BiFeO3 (BFO) films deposited on iridium (It) and platinum (Pt) electrodes have been discussed. 5% Mn-substituted BFO thin films have been formed on Ir/Ti/SiO2/Si(100) and Pt/Ti/SiO2/Si(100) substrates by chemical solution deposition (CSD). X-ray diffraction patterns have proved that BFO films on both Ir and Pt electrodes have distorted rhombohedral R3c structure. It has been found in electrical measurements that leakage current density in the BFO films on Ir electrodes is higher than that in the film on Pt electrode, which is probably due to the lower Schottky barrier height of Ir than Pt. The maximum remanent polarization (P-r) and the minimum coercive electric field in BFO films on Ir electrodes were 82 mu C/cm(2) and 0.3 MV/cm, respectively, at an applied electric field of 2 MV/cm and a measurement frequency of 10 kHz. It has also been found that decrease of the annealing temperature to 525 degrees C is effective to improve the fatigue endurance.