Structure and Dynamics of a Tsai‐type quasicrystal and approximant from 45Sc and 67Zn NMR studies - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Poster De Conférence Année : 2019

Structure and Dynamics of a Tsai‐type quasicrystal and approximant from 45Sc and 67Zn NMR studies

Résumé

NMR is a recognized complementary method to X-rays/Neutron diffusion for structure and dynamics understanding, due to different space-time correlation function probe range, and atomic selectivity. Both benefit from Large Scale Facilities (synchrotron, high field NMR, neutron reactors …) allowing unprecedented space-time resolution. For instance, the family of icosahedral quasicrystals of Tsai type [1,2] contains binary stable i-QC with low chemical disorder that offer the opportunity of precise structural analysis [3] to reconstruct the atomic structure from a 6-dimensional superspace projection, using 1/1 and 2/1 approximant periodic structures as starting models. However, the complexity of superspace crystallography requires assumptions and approximations in order to answer to the question "where are the atoms". Thus, major questions about local structure, dynamics and possible phase transition in the quasicrystal are still to be answered. To the best of our knowledge, no NMR studies have been performed on such iQc. In this presentation, solid-state NMR experiments of 45Sc (I=7/2, 100%) and 67Zn (I=5/2, 4.1%) nuclei at different fields and temperatures, in the 1/1 approximant Zn6Sc and quasicrystal ZnScAg are reported and discussed in the light of structural studies. Both nuclei carry complementary information to probe intershell coupling and tetrahedron induced distorsions. Indeed, 12 scandium atoms constitute the second shell of a Tsai cluster, composed of a tetrahedron (4Zn), dodecahedron (20Zn), Sc icosahedron and larger shells of zinc( Fig.1). Another type of building brick is the double Friauf polyhedron, that exists only in the 2/1 approximant and iQc. We will discuss how our NMR results provide insight in the structure (double Friauf and icosahedral sites) and dynamics (frozen state in the iQc), from comparison between the 1/1 approximant and iQc. References [1] A. P. Tsai, J. Q. Guo, E. Abe, H. Takakura, T. J. Sato, Nature, 2000, 408, 537 [2] A.P. Tsai, Chem. Soc. Rev., 2013, 42, 5352. [3] H. Takakura, C. Pay Gomez, A. Yamamoto, M. de Boissieu, A. P. Tsai, Nat. Mater.,2007, 6,58 Acknowledgements: We acknowledge IRRMN FR3050 CNRS for support of High Field NMR experiments in Lille. This research received FEDER financial support (FEDER 34722-Prin2Tan) for funding NMR spectrometers in Rennes.
Fichier non déposé

Dates et versions

hal-02408464 , version 1 (13-12-2019)

Identifiants

  • HAL Id : hal-02408464 , version 1

Citer

Christophe Odin, Tsunetomo Yamada, Jean-Claude Ameline, Julien Trébosc, Laurent Le Pollès, et al.. Structure and Dynamics of a Tsai‐type quasicrystal and approximant from 45Sc and 67Zn NMR studies. EUROMAR 2018, Jul 2019, NANTES, France. ⟨hal-02408464⟩
66 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More