Investigation of structural and ferroelectric properties of pulsed-laser-ablated epitaxial Nd-doped bismuth titanate films

摘要

Lanthanide doped bismuth titanate films have been shown to exhibit excellent fatigue resistance and higher remanent polarization than SrBi2Ta2O9 films. In this paper we report on the detailed investigation of structural and ferroelectric properties of Nd-doped Bi4Ti3O12 (BNdT) films grown by pulsed laser ablation. Highly epitaxial 300 nm thick (001)-, (118)-, and (104)-oriented BNdT films were deposited on SrRuO3 buffered SrTiO3 substrates of (100), (110), and (111) orientations, respectively. The highest remanent polarization (2P(r)) of similar to40 muC/cm(2) was observed in the (104)-oriented films at a coercive field of similar to50 kV/cm. Leakage currents of the films were of the order of 10(-6)-10(-5) A/cm(2) with (104)-oriented films showing improved behavior. The films showed good fatigue resistance upon bipolar switching up to 10(9) cycles. (C) 2004 American Institute of Physics.