Preparation of acoustic lenses by mechanochemical synthesis and electrophoretic deposition of lead zirconium titanate (PZT) films

PZT powders has been synthesized via reactive dry milling using PbZrO3 and PbTiO3 as starting materials. Stabel suspensions of the PZT particles in ethanol (d50(Vol) = 115 nm) were obtained by a chemomechanical dispersion step. Teh electrophoretic deposition has been optimized varying the cell voltage and the PZT solid content in the suspension. PZT films have been deposited on platinum coated saphire. After drying, the films are densely packed and free of cracks. By using lithium acetate and lead acetate as a sinter aid it was possible to reduce the sintering temperature to 1050°C. A good electrode has been sputtered onto the piezoelectric films which then have been poled by the corona method. The circular PZT dots (...) with a thickness of 1 µm show the expected oscillation resonance at about 2 GHz and can be used in acoustic lenses, for example in acoustic microscopes