Université de Neuchâtel

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

Despont, Laurent ; Koitzsch, Christian ; Clerc, Florian ; Aebi, Philipp ; Lichtensteiger, Céline ; Triscone, Jean-Marc ; Garcia de Abajo, F.J. ; Bousquet, E. ; Ghosez

In: Despont, Laurent ; Institut de Physique, Université de Neuchâtel, Switzerland, 2006, vol. 73, no. 094110, p. 1-6

X-ray photoelectron diffraction is used to directly probe the intracell polar atomic distortion and tetragonality associated with ferroelectricity in ultrathin epitaxial PbTiO3 films. Our measurements, combined with ab initio calculations, unambiguously demonstrate noncentrosymmetry in films a few unit cells thick, imply that films as thin as three unit cells still preserve a...

Université de Neuchâtel

X-ray photoelectron diffraction study of ultrathin PbTiO3 films

Despont, Laurent ; Lichtensteiger, Céline ; Clerc, F. ; Garnier, Michael Bernard Gunnar ; Garcia de Abajo, F.J. ; Van Hove, M. A. ; Triscone, Jean-Marc ; Aebi, Philipp

In: European Physical Journal B (The) - Condensed Matter and Complex Systems, 2006, vol. 49, no. 2, p. 141-146

Full hemispherical X-ray photoelectron diffraction (XPD) experiments have been performed to investigate at the atomic level ultrathin epitaxial c-axis oriented PbTiO3 (PTO) films grown on Nb-doped SrTiO3 substrates. Comparison between experiment and theory allows us to identify a preferential ferroelectric polarization state in a 60 Å -thick PTO film. Multiple scattering...

Université de Neuchâtel

Monodomain to polydomain transition in ferroelectric PbTiO3 thin films with La0.67Sr0.33MnO3 electrodes

Lichtensteiger, Céline ; Dawber, Matthew ; Stucki, Nicolas ; Triscone, Jean-Marc ; Hoffman, Jason ; Yau, Jeng-Bang ; Ahn, Charles H. ; Despont, Laurent ; Aebi, Philipp

In: Applied Physics Letters, 2007, vol. 90, no. 052907, p. 1-3

Finite size effects in ferroelectric thin films have been probed in a series of epitaxial perovskite c-axis oriented PbTiO3 films grown on thin La0.67Sr0.33MnO3 epitaxial electrodes. The film thickness ranges from 480 down to 28 Å (seven unit cells). The evolution of the film tetragonality c/a, studied using high resolution x-ray diffraction...