Atomic structure of the i-R-Cd quasicrystals and consequences for magnetism

T Yamada (1) , H. Takakura (2) , T. Kong (3) , P. Das (3) , W. T. Jayasekara (3) , A. Kreyssig (3) , G Beutier (4) , P. C. Canfield (3) , M N de Boissieu (4) , A. I. Goldmann (3)

1 Tohoku University [Sendai]
2 Hokkaido University [Sapporo, Japan]
3 ISU - Iowa State University
4 SIMaP - Science et Ingénierie des Matériaux et Procédés

We report on the six-dimensional (6D) structural refinement of three members of the i-R-Cd quasicrystals (R = Gd, Dy, Tm) via synchrotron x-ray diffraction from single-grain samples, and show that this series is isostructural to the i-YbCd5.7 quasicrystal. However, our refinements suggest that the R occupancy on the Yb icosahedron sites within the Tsai-type atomic cluster is approximately 80%, with the balance taken up by Cd. Similarities between the i-R-Cd series and i-ScZn7.33, and their differences with i-YbCd5.7 and i-Ca15Cd85, indicate that there are at least two subclasses of Tsai-type icosahedral quasicrystals. We further show from x-ray resonant magnetic scattering (XRMS) measurements on a set of closely related Tb1-xYxCd6 1/1 approximants that the dilution of themagnetic R ions on the icosahedron within the Tsai-type cluster by nonmagnetic Y disrupts the commensurate magnetic ordering in the approximant phase.

Domaines: Matériaux

T Yamada, H. Takakura, T. Kong, P. Das, W. T. Jayasekara, et al.. Atomic structure of the i-R-Cd quasicrystals and consequences for magnetism. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2016, 94 (6), pp.5. ⟨hal-01464059⟩