Effects of substrate temperature on the microstructure and ferroelectric properties of Aurivillius Bi6Ti3Fe2O18 thin films

Aurivillius Bi6Ti3Fe2O18 thin films were deposited by pulsed laser deposition (PLD). X-ray diffraction patterns indicated that the obtained thin films were polycrystalline and belong to orthorhombic F2mm(42) space group. Ferroelectric measurements of as-obtained Bi6Ti3Fe2O18 thin films present an increasement of polarization with increasing substrate temperature which is result from a decrease of leakage current in the films. The positive-up-negative-down (PUND) measurements show switched and non-switched polarization in all of the Bi6Ti3Fe2O18 thin films, which manifest the ferroelectricity in as-deposited thin films. Fatigue-free behavior was obtained in Pt/Bi6Ti3Fe2O18/Pt capacitors. Piezoresponse force microscopy (PFM) measurements show out-of-plane piezoelectric response and demonstrate the ferroelectric polarizability.