Influence of Precursor on Microstructure and Phase Composition of Epitaxial Hydrothermal PbZr0.7Ti0.3O3 Films

Amorphous Zr−Ti hydrous oxide submicrometer spheres were employed in hydrothermal syntheses of PbZr0.7Ti0.3O3 heteroepitaxial thin films on single-crystal SrTiO3 substrates. Reactions utilizing processing variables that included precursor concentration (0.1−0.4 m), KOH concentration (6−12 m), and time (24−60 h) were carried out at 150 °C to evaluate the effect of this precursor on the formation of an epitaxial film. Selected experiments were also conducted to examine how this spherical precursor compares with two other precursor systems, that is, nanostructured amorphous Zr−Ti hydrous oxide prepared by coprecipitation at room temperature, and a mixture of crystalline TiO2 and amorphous ZrO2·nH2O obtained from soluble ZrOCl2·8H2O. On the basis of the results of X-ray diffraction and electron microscopy, precursor choice, precursor concentration, and KOH mineralizer concentration have a significant effect on the quality, composition, and morphology of the film.