Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 8: POSTERS Dynamics and Diffusion
CPP 8.7: Poster
Montag, 25. Februar 2008, 16:45–19:00, Poster A
Deuteron NMR studies on ice II — •Florian Löw1, Marco Scheuermann1, Burkhard Geil2, and Franz Fujara1 — 1Institut für Festkörperphysik, TU Darmstadt, 64289 Darmstadt — 2Experimentelle Physik III, TU Dortmund, 44221 Dortmund
Deuteron spin-lattice relaxation in high pressure ice II has been investigated at different temperatures.
Ice II, one of the high pressure polymorphs of ice, is a completely proton-ordered structure in which two crystallographicly distinguishable types of water molecules form a tetrahedrally linked network of hydrogen bonds.
Deuteron spin-lattice relaxation is sensitive to dynamics in the domain of the Larmor frequency at 46.7 MHz. Measurements at different temperatures of the deuteron spin-lattice relaxation time T1 show that the magnetization recovery is unequivocally non-exponential which indicates a distribution of correlation times.
The samples (D2O) have been prepared at appropriate pressures and temperatures. They can be recovered to ambient pressure at liquid nitrogen temperature where they remain metastable and can be studied. The sample quality is verified by x–ray diffraction. T1–measurements have been performed while increasing the temperature stepwise. At a defined temperature a discontinuity in T1 indicates a phase transition. The high pressure ice phase transforms to crystalline cubic ice Ic.