Field-induced strain of (Pb, La)(Zr, Ti)O3 epitaxial films grown by metal organic chemical vapor deposition

Two micrometers thick (Pb, La)(Zr, Ti)O3 [PLZT] films with wide composition range were epitaxially grown on (1 0 0)SrRuO3 bottom electrode layers epitaxially grown (1 0 0) SrTiO3 substrates by metal organic chemical vapor deposition. Constituent phase of the films were found to be almost the same with the reported phase diagram for the sintered body except for the wider coexistence region of tetragonal and rhombohedral phases. The change of the measured field-induced strain with the electric field was almost respond to the square of the polarization of the films except the negative strain region, but the magnitude was different. This is due to the increase of the electrostatic coefficient of the film with increasing the La/(Pb + La) ratio. As a results, field induced strain of the PLZT film was found to be controlled by adjusting the composition of PLZT films.