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.
Acknowledgements
The authors wish to acknowledge the invaluable assistance of, and discussions with, C.-S. Ho, X. Lin, A. Kracher, K.W. Dennis, R.W. McCallum, T. Lograsso, M.J. Kramer and P. Thiel. Work at the Ames Laboratory was supported by the US Department of Energy, Basic Energy Sciences under Contract No. DE-AC02-07CH11358. The use of the Advanced Photon Source was supported by the US DOE under Contract No. DE-AC02-06CH11357.