Dresden 2011 – scientific programme
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DF: Fachverband Dielektrische Festkörper
DF 12: Poster
DF 12.16: Poster
Wednesday, March 16, 2011, 15:00–17:30, P1
Lattice dynamics of HgI2 — •Lydia Nemec1,2, Dieter Strauch1, Bruno Dorner3, Dieter Schwarzenbach4, Peter Fischer5, and Martin Böhm3 — 1Universität Regensburg, Regensburg, Deutschland — 2current address: Fritz Haber Institut der Max Planck Gesellschaft, Berlin, Deutschland — 3Institut Laue-Langevin, Grenoble, France — 4Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland — 5Paul Scherrer Institute, Villingen, Switzerland
We present a first principle study of the vibrational properties of tetragonal red mercury(II)iodide (α-HgI2), an important material for X- and γ-ray detection at room temperature. Linear response theory within density-functional theory is used to calculate phonon frequencies and eigenvectors with special emphasis on vibrations in the [110]-plane. The full phonon band structure is investigated and compared with experimental data. We study the LO-TO splitting by calculating the dielectric constant and Born effective charges. The theoretical scattering intensities show fair agreement with experiment. Predictions are made for the scattering intensities in the [110]-direction, and data are provided for future neutron scattering experiments.