Antiferromagnetic order and the structural order-disorder transition in the Cd₆Ho quasicrystal approximant

Journal Article · Mon Sep 22 00:00:00 EDT 2014 · Philos. Mag. Lett.

DOI:https://doi.org/10.1080/09500839.2013.815375· OSTI ID:1091412

Kreyssig, Andreas; Beutier, Guillaume; Hiroto, Takanobu; Kim, Min Gyu; Tucker, Gregory S.; de Boissieu, Marc; Tamura, Ryuji; Goldman, Alan I. ^[1]

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1. CNRS-UMR

It has generally been accepted that the orientational ordering of the Cd₄ tetrahedron within the Cd₆ R quasicrystal approximants is kinetically inhibited for R = Ho, Er, Tm and Lu by steric constraints. Our high-resolution X-ray scattering measurements of the Cd₆Ho quasicrystal approximant, however, reveal an abrupt (first-order) transition to a monoclinic structure below T _S = 178 K for samples that have ‘aged’ at room temperature for approximately one year, reopening this question. Using X-ray resonant magnetic scattering at the Ho L ₃-edge we have elucidated the nature of the antiferromagnetic ordering below T _N = 8.5 K in Cd₆Ho. The magnetic Bragg peaks are found at the charge forbidden H + K + L = 2n + 1 positions, referenced to the high-temperature body-centred cubic structure. In general terms, this corresponds to antiferromagnetic arrangements of the Ho moments on adjacent clusters in the unit cell as previously found for Cd₆Tb.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: USDOE Office of Science (SC)
• OSTI ID: 1091412
• Journal Information: Philos. Mag. Lett., Vol. 93, Issue (9) ; 2013
• Country of Publication: United States
• Language: ENGLISH