Dresden 2006 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.127: Poster

Donnerstag, 30. März 2006, 16:00–18:00, P1

Features of phonon densities of some FCC metals — •Elena V. Manzhelii, Igor A. Gospodarev, Vladimor O. Kruglov, and Sergey Feodosyev — B.Verkin ILTPE NAS of Ukraine 47 Lenin Ave., Kharkov 61103 , UKRAINE

The behavior of the phonon densities near the Van Hove singularities has been investigated using the force constants of the interatomic interaction that were obtained from experimental results for elastic constants [1]. The calculation was performed by the Jacobian matrix method, which permitted us to analyze the contribution to the spectral densities from the phonons propagating in all directions (not in the high-symmetry ones). This procedure enabled us to detect an additional singularity in some metals, such as Cu, Au and Al. The singularity was detected near the upper edge of the continuum spectrum band and was due to the nonmonotonous character of the dispersion curves and the maximum frequency inside the Brillouin zone. Such singularity is absent in some metals (e.g. Ag). The relaxation of the force constants at the sample boundaries (surfaces, ribs, apexes) has been investigated.

1. S.B. Feodsyev, I.A. Gospodarev, V.O. Kruglov, E.V. Manzhelii, Condensed Matter Division, SIYI41, Prague 2004.