High-energy X-ray diffraction studies of i-Sc₁₂Zn₈₈

Abstract

Although quasicrystals form in a wide variety of ternary and quaternary metallic alloys, examples of stable binary icosahedral quasicrystals are quite rare. Indeed, it has been a decade since the discovery of icosahedral phases in Yb-Cd and Ca-Cd. We have discovered millimeter-sized facetted grains of i-Sc12Zn88 with icosahedral (pentagonal dodecahedral and rhombic triacontahedral) morphologies in solution-grown samples. Structural characterization of the bulk icosahedral phase was accomplished through single-grain high-energy X-ray diffraction. For both growth morphologies, all diffraction peaks could be indexed by a primitive (P-type) icosahedral phase. The two types of morphology do, however, present interesting differences in their respective degrees of quasicrystalline order.Although quasicrystals form in a wide variety of ternary and quaternary metallic alloys, examples of stable binary icosahedral quasicrystals are quite rare. Indeed, it has been a decade since the discovery of icosahedral phases in Yb-Cd and Ca-Cd. We have discovered millimeter-sized facetted grains of i-Sc 12 Zn 88 with icosahedral (pentagonal dodecahedral and rhombic triacontahedral) morphologies in solution-grown samples. Structural characterization of the bulk icosahedral phase was accomplished through single-grain high-energy X-ray diffraction. For both growth morphologies, all diffraction peaks could be indexed by a primitive (P-type) icosahedral phase. The two types of morphology do, however, present interesting differences in their respective degrees of quasicrystalline order.

Magnetism in icosahedral quasicrystals: current status and open questions

“…The powder diffraction peak widths were quite narrow indicating a high degree of structural order in these samples and, in particular, there was no visible dependence of the peak widths on the phason momentum, [94], indicating the absence of any significant frozen in phason strain [95]. Both the dc and ac susceptibility exhibited features at consistent with SG freezing.…”

Quasicrystals: diversity and complexity

“…Their discovery was of great importance, not only because it demonstrated that one does not require three different metals to stabilize a quasicrystal; owing to their relative simplicity, binary quasicrystals allowed for the first essentially complete structural solution of an icosahedral quasicrystal [3]. It was therefore very exciting to hear Alan Goldman's presentation of a new binary quasicrystal-icosahedral Sc 12 Zn 88 [4]. The new AgInYb icosahedral quasicrystal [5], which is believed to be isostructural to the i-CdYb quasicrystal, with Cd being replaced by AgIn, was presented by Marc de Boissieu [6], and shown to display superb crystal quality lending itself to detailed quantitative studies of phason modes.…”

“…This is especially true for the growth of high-quality single crystals, using various techniques like the flux growth method used for the new binary i-Sc 12 Zn 88 system [4]. The effort to offer excellent single-grain samples for careful studies of physical properties was very active in recent years, and received a particular boost in Europe thanks to the CMA Network of Excellence, which focused a significant effort (both in terms of funding and human resources) on disseminating such samples, as shown in Figure 1.…”

A Sodium‐Containing Quasicrystal: Using Gold To Enhance Sodium’s Covalency in Intermetallic Compounds

“…The diffraction peaks of the icosahedral quasicrystal can be indexed using 6D space according to the Elsers method. [23] Received: August 31, 2012 Published online: November 28, 2012 4 (see the Supporting Information, Table S1) was selected for diffraction measurements by using a newly developed high-energy X-ray precession camera technique on station 6ID-D at the Advanced Photon Source.…”

“…4 (see the Supporting Information, Table S1) was selected for diffraction measurements by using a newly developed high-energy X-ray precession camera technique on station 6ID-D at the Advanced Photon Source. [23] Received: August 31, 2012 Published online: November 28, 2012…”