Summary: Misfit strain­film thickness phase diagrams and related
electromechanical properties of epitaxial ultra-thin
lead zirconate titanate films
Q.Y. Qiu a
, R. Mahjoub a
, S.P. Alpay b
, V. Nagarajan a,*
a
School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia
b
Materials Science and Engineering Program and Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
Received 19 March 2009; received in revised form 7 August 2009; accepted 29 September 2009
Available online 24 October 2009
Abstract
The phase stability of ultra-thin (0 0 1) oriented ferroelectric PbZr1­xTixO3 (PZT) epitaxial thin films as a function of the film com-
position, film thickness, and the misfit strain is analyzed using a non-linear Landau­Ginzburg­Devonshire thermodynamic model taking
into account the electrical and mechanical boundary conditions. The theoretical formalism incorporates the role of the depolarization
field as well as the possibility of the relaxation of in-plane strains via the formation of microstructural features such as misfit dislocations
at the growth temperature and ferroelastic polydomain patterns below the paraelectric­ferroelectric phase transformation temperature.
Film thickness­misfit strain phase diagrams are developed for PZT films with four different compositions (x = 1, 0.9, 0.8 and 0.7) as a

Source: Alpay, S. Pamir - Department of Materials Science and Engineering, University of Connecticut

Collections: Materials Science