RESUMO
Crack-free and dense BaTiO(3) films 4 to 8 mum thick were prepared by spinning a solution of metalloorganic precursors onto an appropriate substrate, and firing and annealing the film in air at certain temperatures to obtain appropriate grain sizes. The electrical properties of the films were studied as a function of grain size, temperature, frequency, and DC bias. Films with a grain size of 0.2 mum showed ferroelectric properties similar to bulk BaTiO(3).
RESUMO
The dielectric constant and spontaneous polarization of fine-grained BaTiO(3) prepared from powder produced by metalloorganic decomposition technology were studied. The room-temperature dielectric constant of BaTiO(3) was found to increase sharply with increase in grain size, reach a maximum at about 0.4 mum, and decrease with further increase in grain size. Spontaneous polarization continuously decreased with decrease in grain size. A model is proposed to explain the grain size dependence of the dielectric constant.
RESUMO
Ferroelectric PbTiO(3) films 0.5- to 2.0-mum thick were prepared by the metalloorganic decomposition (MOD) process using multilayer spinning with firing temperatures of 490-630 degrees C. The temperature dependence of the dielectric constant was found to be a function of the c/a ratio, which could be modified by control of either the single-layer thickness or the strength of the electric field during film preparation near the Curie temperature. The films were near theoretical density and defect-free over 2 cmx2 cm areas.
