Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/10582
Title: Contribution of low-frequency modes to the specific heat of Cu-Zn-Al shape-memory alloys
Author: Lashley, J. C.
Drymiotis, F. R.
Safarik, D. J.
Smith, J. L.
Romero, Ricardo
Fisher, R. A.
Planes Vila, Antoni
Mañosa, Lluís
Keywords: Dispersió (Física nuclear)
Fonons
Aliatges
Scattering (Physics)
Phonons
Alloys
Issue Date: 2007
Publisher: The American Physical Society
Abstract: We report a comparison of the specific-heat measurements on isoelectronic Cu-Zn-Al shape-memory alloys in the parent cubic phase L21 and in the close-packed martensitic phase 18R. Measurements were made by thermal-relaxation calorimetry over the temperature range 1.9 T 300 K. For the close-packed martensitic phase we find that the specific heat behaves similarly to that of pure copper which is also close packed. However, we observe deviations from Debye behavior for the cubic phase at low temperatures. This deviation is accounted for by the addition of 5% of Einstein localized modes to the Debye modes. Although the microscopic origin remains unknown, it was anticipated that it is related to the well-known softening of the TA2 110 phonon branch. In order to address this hypothesis an analysis of the lattice heat capacity of the cubic phase was compared to the calculated lattice heat capacity of -brass, as determined by integrating over the phonon density of states. A similar comparison was made between the close-packed phase and -brass.
Note: Reproducció digital del document publicat en format paper, proporcionada per http://dx.doi.org/10.1103/PhysRevB.75.064304
It is part of: Physical Review B, 2007, vol. 75, núm. 6, p. 064304-1-064304-7
Related resource: http://dx.doi.org/10.1103/PhysRevB.75.064304
URI: http://hdl.handle.net/2445/10582
ISSN: 0163-1829
Appears in Collections:Articles publicats en revistes (Física Quàntica i Astrofísica)

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