Berlin 2012 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 7: 100 years since the Laue experiment: Topical aspects of diffraction and scattering (Joint Session KR, BP, CPP, DF, GP, MA, MI, MM; related to SYXD)

DF 7.2: Vortrag

Dienstag, 27. März 2012, 10:00–10:15, EMH 225

Thermal diffuse scattering as a complementary tool in the study of lattice dynamics — Björn Wehinger, Alexeï Bosak, and •Michael Krisch — ESRF, 6 Rue Jules Horowitz, BP 220, 38043 Grenoble, France

Thermal diffuse scattering (TDS) in combination with inelastic x-ray scattering (IXS) and lattice dynamics calculations allows the reconstruction of the lattice dynamics in the entire Brillouin zone. X-ray scattering by thermally populated phonons in crystals reduces the intensity of Bragg spots and substantially increases the intensity of the diffuse scattering which has a rich structure in reciprocal space [1,2]. In combination the two techniques can serve as a rigorous benchmark for parameter free lattice dynamics calculations [3]. The proposed method can be used for the precise detection of mode softening, for the study of lattice dynamics under extreme conditions and for time resolved measurements. In metallic systems it is possible to map the Fermi surface in tree dimensions by directional tracing of Kohn anomalies [4]. The presented results on β-tin illustrate the functionality of the proposed combined approach with new insights into the dynamical properties on this system.

[1] Wooster, Diffuse X-ray reflections from crystals, Clarendon Press, Oxford (1962)

[2] Xu RQ, Chiang TC, Z. Kristallogr. 220, 1009 (2005)

[3] A. Bosak, et al., Z. Kristallogr. preprint: doi: 10.1524/zkri.2012.1432

[4] A. Bosak, et al., PRL, 103, 076403 (2009)