STRUCTURE AND PROPERTIES OF COMPOSITIONALLY GRADED Pb O₃ FERROELECTRIC THIN FILMS

Compositionally graded Pb (Zr, Ti) O₃ thin films were prepared on platinum-coated silicon substrates by Sol-Gel method and rapid heat-treatment. The composition depth profile of a typical up-graded film was determined by using a combination of Auger electron spectroscopy and Ar ion etching. The results confirm that the processing method produces graded composition change. XRD analysis shows that the graded thin films possess a tetragonal and rhombohedral composite structure. The curves of C-T and tgδ-T for the down-graded Pb (Zr_<em>xTi_1-x)O₃ thin films show an F-F phase transition temperature, two Curie temperatures and the frequency dispersion phenomenon. The hysteresis loops of the graded thin films show fine ferroelectric properties. The pyroelectric coefficients of the graded thin films gradually increase with temperature, and are higher than that of every unit thin film.