DYNAMICS OF POLARIZATION LOSS IN (PB, LA)(ZY, TI)O-3 THIN-FILM CAPACITORS

We report results of high-speed polarization relaxation measurements i n ferroelectric thin film capacitors. Polarization relaxation has been reported to occur in two distinct time regimes, one for relaxation ti mes in the range of a few milliseconds and a second for longer relaxat ion times. We find that the polarization relaxation in the first regim e is governed by at least two different physical processes, namely dep oling fields and the activation field for switching. Using prototypica l epitaxial PbZr0.2Ti0.8O3 and Pb0.9La0.1Zr0.2Ti0.8O3 test capacitors, we demonstrate the effect of film microstructure and switching speed on the relaxation dynamics in the first regime. (C) 1998 American Inst itute of Physics. [S0003-6951(98)03125-8].