PLZT thick films for pyroelectric sensors

The production of thick-film (TF) PLZT layers for pyroelectric sensors prepared from perovskite-type (Pb,La)(Zr,Ti) powders is described. The powder manufacture, paste preparation and layer production processes are detailed and flow charts of the powder and layer production and diagrams of the layer structure are presented. The relative permittivity and dielectric loss of PLZT layers were measured as functions of temperature. The temperature dependence of the pyroelectric coefficient was measured and the influence of the poling electric field on the pyroelectric coefficient was investigated. The room-temperature pyroelectric coefficients of the PLZT layers are of the order of and are comparable with commonly used materials, but thick-film technology offers the advantage of a mature and simplified production route. The experimental results made it possible to define parameters for the production process necessary to achieve improved layers for pyroelectric sensors.