Thin pyroelectric PLZT film obtained with sol-gel technology

The sol-gel technology (J. Zarzycki in J.Sol-Gel Sci. Technol. 8:17–22, 1997) and the spin coating were employed for the production of PLZT 12/40/60 pyroelectric film. The starting materials were: lead acetate, lanthanum nitrate, metallo-organic compounds of zirconium and titanium and acetic acid. An alumina substrate with pre-deposited lanthanum-strontium cobalt oxide (LSCO) (H. Takahashi, et al in Phys. Rev. B. 57:15211–15218, 1998) bottom electrode was spin-coated with a sol several times. Following, the film was rapidly thermally processed. To obtain a continuous PLZT film these two operations were repeated a few times. The top electrode, made from LSCO, was subsequently applied on the PLZT film. The produced film has a lower pyroelectric coefficient than bulk ceramics and thick films formerly produced. Figure of merit F _v relating to the voltage responsivity is higher than those of the two earlier materials, due to much lower relative permittivity. The important advantage of applied method is that it requires much lower processing temperature (680°C) than that (1,150°C) needed to produce bulk and thick-film sensors.