The effect of crystallographic orientation and solution aging on the electrical properties of sol-gel derived Pb(Zr_(0.45)Ti_(0.55))O_3 thin films

摘要

Lead zirconate titanate-Pb(Zr_(0.45)Ti_(0.55))O_3 thin films are grown on Pt<111>/Ti/SiO_2/Si<100> substrates by a sol-gel method with <1 0 0>/<0 0 1> and <1 1 1> preferred orientations. Film orientation was controlled mainly by the annealing process and temperature. Films with <1 0 0>/<0 0 1> orientation consist of a uniform microstructure with micron size grains, whereas films with <111> orientation contain sub-micron grains. The electrical properties were influenced markedly by the microstructure and orientation of the films. The <1 1 1> oriented films exhibit a square-like hysteresis loop with remnant polarization (P_r) reaching 46 mu C/cm~2 under 550 kV/cm, whereas <1 0 0>/<0 0 1> oriented films have a P_r of 20 mu C/ cm~2 with more slim hysteresis curves. Aging of the precursor solutions resulted in films growing with <1 0 0>/<0 0 1> texture and displaying inferior electrical properties.