Dielectric and electrical properties of preferentially (111) oriented Zr-rich 0.1Pb(Mg1/3Nb2/3)O3-0.9Pb(ZrxTi1-x)O3 thin films by chemical solution deposition

Ferroelectric thin films with rhombohedral composition of 0.1Pb(Mg1/3Nb2/3)O-3-0.9Pb(ZrxTi1-x)O-3 (0.6 less than or equal tox less than or equal to0.9) have been prepared by a chemical solution deposition on the (111) Pt/Ti/SiO2/Si substrates. The films were consisted of nearly pure perovskite phases with the (111) preferred orientation. Fine grains below approximately 200 nm in average size tended to be the clusters of grains when x was higher than 0.8. The dielectric constant of the films, which gradually decreased with x, showed a minimum (similar to 650) at the composition of x=0.9. Meanwhile the values of remanent polarization (P-r) of the films increased with x up to 0.8 and then decreased for x=0.9. The increasing tendency is thought to be due to the preferred (111) orientation and distortion of perovskite unit cell. While the decreased polarization properties of x=0.9 implies the role of antiferroelectric properties of the lead zirconate phase, which can be possibly explained by DC bias-dependent capacitance behavior. The storage charge densities of the films decreased with x, but significantly increased upon the field-induced ferroelectric phase transition of the films. (C) 2001 Elsevier Science B.V. All rights reserved.