Lattice dynamics of the Zn-Mg-Sc icosahedral quasicrystal and its Zn-Sc periodic 1/1 approximant

TitleLattice dynamics of the Zn-Mg-Sc icosahedral quasicrystal and its Zn-Sc periodic 1/1 approximant
Publication TypeJournal Article
Year of Publication2007
AuthorsDe Boissieu M, Francoual S, Mihalkovic M, Shibata K, Baron AQR, Sidis Y, Ishimasa T, Wu D, Lograsso T, Regnault LP, Gahler F, Tsutsui S, Hennion B, Bastie P, Sato TJ, Takakura H, Currat R, Tsai AP
Journal TitleNature Materials
Volume6
Pages977-984
Date PublishedDec
Type of ArticleArticle
ISBN Number1476-1122
Accession NumberISI:000251317000021
Keywordsalloys, CONDUCTIVITY, modes, neutron-scattering, phase, phonons, RECIPROCAL SPACE, YB
Abstract

Quasicrystals are long-range-ordered materials that lack translational invariance, so the study of their physical properties remains a challenging problem. Here, we have carried out inelastic-X-ray- and neutron-scattering experiments on single-grain samples of the Zn-Mg-Sc icosahedral quasicrystal and of the Zn-Sc periodic cubic 1/1 approximant, with the aim of studying the respective influence of the local order and of the long-range order ( periodic or quasiperiodic) on lattice dynamics. Besides the overall similarities and the existence of a pseudo-gap in the transverse dispersion relation, marked differences are observed, the pseudo-gap being larger and better defined in the approximant than in the quasicrystal. This can be qualitatively explained using the concept of a pseudo-Brillouin-zone in the quasicrystal. These results are compared with simulations on atomic models and using oscillating pair potentials, and the simulations reproduce in detail the experimental results. This paves the way for a detailed understanding of the physics of quasicrystals.

DOI10.1038/nmat2044
Alternate JournalNat. Mater.