Berlin 2008 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 7: Point defect spectroscopy and engeneering

DF 7.6: Vortrag

Dienstag, 26. Februar 2008, 12:20–12:40, EB 107

Solid-state NMR on defects in lead titanates — •Marko Bertmer¹, Rüdiger Eichel², and Hans Kungl³ — ¹Experimentelle Physik 2, Leipzig, Deutschland — ²Physikalische Chemie III, Darmstadt, Deutschland — ³Institut für Keramik im Maschinenbau, Karlsruhe, Deutschland

Failure of ferroelectrics is not well understood. In our approach, we employ various solid-state NMR techniques to characterize and quantify chemical structures that arise from crystallographic defects. Especially, the existence and distributions of ¹H as water or other species is a primary goal in our research.

¹H spectra are known to be often of low resolution due to the strong homonuclear dipolar coupling. With sophisticated NMR techniques, e. g. echo methods and multiple quantum transitions, we want to get more insight into the defect structures. This enables both improvement in spectral resolution as well as to obtain information about the dynamics of present chemical structures such as water.

Additionally, all nuclei present in lead titanates are accessible by NMR with different degree of sensitivity. Especially, with self-built equipment we are able to increase the abundance of the ¹⁷O nuclei and therefore allow for detection.