Three-Domain Architecture of Stress-Free Epitaxial Ferroelectric Films
Alexander L. Roytburd, S P. Alpay, V Nagarajan, Leonid A. Bendersky, R Ramesh
Epitaxial ferroelectric films undergoing a cubic-tetragonal phase transformation relax internal stresses due to the structural phase transformation and the difference in the thermal expansion coefficients of the film and the substrate by forming polydomain structures. The most commonly observed polydomain structure is the c/a/c/a polytwin which relieves the internal stresses only partially. Relatively thicker films may completely reduce internal stress if all three variants of the ferroelectric phase are brought together such that the film has the same in-plane size as the substrate. In this Letter, we provide experimental evidence on the formation of the 3-domain structure based on transmission electron microscopy in 450 nm thick (001) PbZr(sub0.2)Ti(sub0.8)O(sub3) films on (001) SrTiO(sub3) grown by pulsed laser deposition. X-ray diffraction studies show that the film is fully relaxed. Experimental data is analyzed in terms of a domain stabilty map. It is shown that the observed structure in epitaxial ferroelectric films is due to the interplay between relaxation by misfit dislocations at the deposition temperature and relaxation by polydomain formation below the phase transformation temperature.
Journal of Applied Physics
domains, ferroelectric, films, PZT, TEM
, Alpay, S.
, Nagarajan, V.
, Bendersky, L.
and Ramesh, R.
Three-Domain Architecture of Stress-Free Epitaxial Ferroelectric Films, Journal of Applied Physics
(Accessed February 27, 2024)