Book/Report

FZJ-2018-00578

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Schwingungsverhalten von Zwischengitteratomen

Zeller, R. (Corresponding author)FZJ*

1975
Kernforschungsanlage Jülich, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/16606

Report No.: Juel-1259

Abstract: The vibrational behaviour of crystals with point defects, especially with self-interstitials, is discussed with particular emphasis on defect-induced resonant and localised modes. For low-frequency resonant modes, an analytical expression for the Green's function of the defect is derived starting from a method due to Krumhansl and Matthew. The Green's function has the form of the Green's function of an onedimensional oscillator with an effective force constant f$^{eff}$, an effective mass M$^{eff}$ and a velocity-dependent damping determined by f$^{eff}$ and M$^{eff}$. Simple approximations for these effective quantities are given. The vibrational properties of self-interstitials in the octahedral and 100-dumbbell configuration in a fee lattice are treated in detail. For simple forceconstant-models the local frequency spectra are calculated for both configurations showing that the interstitial only vibrates with high-frequency localised modes and with low-frequency resonant modes. Furthermore the influence of the resonant modes on physical properties such as the change of elastic constants of phonon dispersion curves and of specific heat is discussed.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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Database coverage:

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