Change search
ReferencesLink to record
Permanent link

Direct link
Anomalous vibrational dynamics in the Mg(2)Zn(11) phase
Show others and affiliations
2011 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 83, no 14, 144202- p.Article in journal (Refereed) Published
Abstract [en]

We present a combined experimental and theoretical study of the structure and the lattice dynamics in the complex metallic alloy Mg(2)Zn(11), by means of neutron and x-ray scattering, as well as ab initio and empirical potential calculations. Mg(2)Zn(11) can be seen as an intermediate step in structural complexity between the simple Laves-phase MgZn(2) on one side, and the complex 1/1 approximants and quasicrystals ZnMgAl and Zn(Mg)Sc on the other. The structure can be described as a cubic packing of a triacontahedron whose center is partially occupied by a Zn atom. This partially occupied site turned out to play a major role in understanding the lattice dynamics. Data from inelastic neutron scattering evidence a Van Hove singularity in the vibrational spectrum of Mg(2)Zn(11) for an energy as low as 4.5 meV, which is a unique feature for a nearly-close-packed metallic alloy. This corresponds to a gap opening at the Brillouin zone boundary and an interaction between a low-lying optical branch and an acoustic one, as could be deduced from the dispersion relation measured by inelastic x-ray scattering. Second, the measured phonon density of states exhibits many maxima, indicating strong mode interactions across the whole energy range. The origin of the low-energy modes in Mg(2)Zn(11) and other features of the vibrational spectra are studied, using both ab initio and empirical potential calculations. A detailed analysis of vibrational eigenmodes is presented, linking features in the vibrational spectrum to atomic motions within structural building blocks.

Place, publisher, year, edition, pages
2011. Vol. 83, no 14, 144202- p.
National Category
Chemical Sciences
URN: urn:nbn:se:su:diva-68843DOI: 10.1103/PhysRevB.83.144202ISI: 000289229200003OAI: diva2:473743
authorCount :15Available from: 2012-01-07 Created: 2012-01-07 Last updated: 2012-01-07Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Lidin, Sven
By organisation
Department of Materials and Environmental Chemistry (MMK)
In the same journal
Physical Review B. Condensed Matter and Materials Physics
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 16 hits
ReferencesLink to record
Permanent link

Direct link