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Direct evidence for ferroelectric polar distortion in ultrathin lead titanate perovskite films

L. Despont·C. Lichtensteiger·C. Koitzsch·C. Clerc·M. G. Garnier·F. J. Garcia de Abajo·E. Bousquet·Ph. Ghosez·J. -M. Triscone·P. Aebi
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Abstract

X-ray photoelectron diffraction is used to directly probe the intra-cell polar atomic distortion and tetragonality associated with ferroelectricity in ultrathin epitaxial PbTiO3 films. Our measurements, combined with ab-initio calculations, unambiguously demonstrate non-centro-symmetry in films a few unit cells thick, imply that films as thin as 3 unit cells still preserve a ferroelectric polar distortion, and also show that there is no thick paraelectric dead layer at the surface.

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L. Despont, C. Lichtensteiger, C. Koitzsch, C. Clerc, M. G. Garnier, F. J. Garcia de Abajo, E. Bousquet, Ph. Ghosez, J. -M. Triscone, P. Aebi. 2005-11-03. Direct evidence for ferroelectric polar distortion in ultrathin lead titanate perovskite films. https://doi.org/10.1103/physrevb.73.094110

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