The effect of crystallographic orientation and solution aging on the electrical properties of sol–gel derived Pb(Zr0.45Ti0.55)O3 thin films

Lead zirconate titanate—Pb(Zr0.45Ti0.55)O3 thin films are grown on Pt〈1 1 1〉/Ti/SiO2/Si〈1 0 0〉 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 〈1 1 1〉 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 (Pr) reaching 46 μC/cm2 under 550 kV/cm, whereas 〈1 0 0〉/〈0 0 1〉 oriented films have a Pr of 20 μC/cm2 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.