Berlin 2015 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 6: Poster Session DF

DF 6.2: Poster

Montag, 16. März 2015, 19:00–21:00, Poster C

Water-Lithiumniobate Interface from Ab initio Molecular Dynamics — •Rebecca Hölscher, Simone Sanna, and Wolf Gero Schmidt — Universität Paderborn

LiNbO₃ (LN) has been intensively used since decades for various optical and acoustic applications due to its pronounced piezoelectric, pyroelectric, and photorefractive properties and optical nonlinearities. More recently, the possibility to manipulate locally the surface reactivity and surfaces properties by means of polarization reversal of ferroelectric domains has stimulated interest in novel applications from the areas of e.g. nanochemistry or molecular detectors[1].

In order to effectively exploit the phenomena related to the strong and switchable electric fields at ferroelectric surfaces, a detailed microscopic understanding is indispensable. Previous studies [2,3] indicate a highly specific adsorption behaviour of water molecules depending on the surface polarization for water thin films of monolayer thickness. Here we extend the study to the interface between bulk water and LN and perform ab initio molecular dynamics at a wide temperature range. The result show a layered water structure below and slightly above the freezing temperature.

At higher temperatures the molecular water clusters dissolve and the water double layer cannot be recognized anymore.

[1] D. Li, M. H. Zhao, et al., Nat. Mat. 7, 473 (2008)

[2] S. Sanna, R. Hölscher, W.G. Schmidt, PRB 86, 205407 (2012)

[3] S. Rode, R. Hölscher, et al., PRB 86, 075568 (2012)