Microstructure and properties of sol-gel processed Pb1-xLax(Zr-0.52, Ti-0.48)(1-x/4)O-3 thin films. The effects of lanthanum content and bottom electrodes

PLZT {lanthanum doped PZT [Pb(Zr-0.52, Ti-0.48)O-3} thin films with 5, 8 an d 10 mol% lanthanum were processed via chemical solution deposition on (111 )-Pt/TiO2/SiO2/Si (100) and LaNiO2 (LNO)/(111)-Pt/TiO2/SiO2/Si (100). The t hin films were investigated in terms of the influence of lanthanum content and substrate heterolayer structure on the microstructure and dielectric pr operties. It is shown that deposition on (111)-Pt leads to a (100)/(111) pr eferred texture and a coarse grained microstructure with PbO depleted areas . Deposition on LNO results in a randomly oriented, fine grained microstruc ture. The dielectric constants decrease with increasing lanthanum content a nd are higher for the films deposited on Pt. They take values between 1630 (0.05 mol La3+) and 865 (0.1 moI La3+) for deposition on Pt and between 109 0 and 808 for deposition on LNO. The fatigue properties depend also on the lanthanum content and substrate type. The PLZT thin films with lanthanum co ncentration above 0.05 deposited on LNO show no fatigue. (C) 2001 Elsevier Science B.V. All rights reserved.