MICROSTRUCTURE AND ELECTRICAL PROPERTIES OF Pb(Zr0.65Ti0.35)O3 THIN FILMS GROWN ON OXIDE SUBSTRATES

Abstract

Pb(Zr0.65Ti0.35)O3 (PZT) thin films were deposited on SrRuO3 (SRO) buffer layer coated LaAlO3 (LAO) substrates by RF sputtering method. X-ray diffraction analyses indicate that the PZT thin films show epitaxial orientation and the in-plane epitaxial relationship between film and substrate is deduced as (001)[010] PZT ‖(001)[010] SRO ‖(001)[010] LAO . Despite the Zr -richcomposition, observations using transmission electron microscopy reveal that the PZT thin films exhibited tetragonal phase, which was due to the clamping effect of the substrates. The clamping effecton the electrical properties, especially on the dielectric properties, was evaluated. Ferroelectric measurements show that PZT films with LAO/SRO substrates were fatigue-free. However, the test of dielectric property dependences on temperature manifests a relatively low Curie temperature of the PZT films. The loss tangent decreasedwith increase intemperature. Owing to the release of clamping stress, the loss tangent decreased dramatically while the temperature was approaching the phase transition temperature of PZT thin films.