Fabrication of PbBi4Ti4O15 and Pb2Bi4Ti5O18 thin films by sol-gel method

PbBi4Ti4O15(PBT) and Pb2Bi4Ti5O18(P2BT) thin films were fabricated on Pt/Ti/SiO2/Si substrates by sol-gel method, and their ferroelectric properties were investigated. Two processes were examined for the preparation of PET thin films. In the process which used Bi-acetate as a starting material, the single PET phase thin films could be obtained by inserting a Bi-rich buffer layer between the Pt electrode and the PET him. In the other process which used Bi-Ti complex alkoxide, the PET single phase was obtained without the buffer layer. P2BT thin films prepared by the latter process showed about two times larger remnant polarization (2P(r)) values of 12 mu C/cm(2) compared with 2P(r) = 7 mu C/cm(2) for the PET thin him, coinciding with the tendency reported for single crystals. Both the PET and P2BT thin films showed good fatigue endurance up to 1 x 10(9) switching cycles.