Electrophoretic deposition of ferroelectric thin films

Abstract

Doped lead zirconate titanate (PZT) thin films have been deposited by electrophoresis from suspensions of commercial PZT powder in acetone with additions of nitric acid and nitrocellulose. Suspension characteristics have been examined by zeta potential measurements. It is shown that the suspension chemistry has a marked effect so that acid concentration, binder additions and suspension age all combine to change the zeta potential and therefore the quality of the deposit. The effect of deposition/firing schedule on microstructure of the final film have been studied. Films upto 10μm thick can be produced by a multiple deposition and sintering method. Measurements of dielectric constant and dielectric loss as a function of frequency have been made before and after poling. A pyroelectric coefficient of 266μCm⁻²K⁻¹ has been measured and the pyroelectric figure of merit calculated to be 1.28 × 10⁻⁵Pa^−½. The films have been shown to exhibit a piezoelectric response after poling.