Reversibility of the Perovskite-to-Fluorite Phase Transformation in Lead-Based Thin and Ultrathin Films


  • Michoel J. Rye provided essential technical assistance in the characterization of these films. The authors would also like to thank P. A. Mahoney and J. S. Wheeler for their technical assistance and valuable input into this project. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.


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As film thicknesses decrease below 50 nm, control of cation stoichiometry in Pb-based dielectrics becomes increasingly difficult, a problem that is exacerbated by interaction with technologically important Pt bottom electrodes. Post-crystallization annealing in a Pb-rich atmosphere is shown to be a general technique to reversibly convert low-permittivity Pb-deficient fluorite into ferroelectric high-permittivity stoichiometric perovskite with outstanding dielectric properties (see figure).