Icosahedral quasicrystalline and hexagonal approximant phases in the Al-Mn-Be alloy system

S. H. Kim, G. S. Song, E. Fleury, K. Chattopadhyay, W. T. Kim, D. H. Kim

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

We report the formation of a primitive icosahedral quasicrystal with increased stability in Al-Mn-Be alloys close to the compound Al15Mn3Be2by melt spinning and injection casting. The crystal structure of this compound was unknown. We show that in as-cast as well as heat treated condition the intermetallic phase HI has a hexagonal structure with lattice parameters a = 1.2295 nm and c = 2.4634 nm. The space group is P63/mmc. In the injection-cast samples, the quasicrystal coexists with another closely related hexagonal phase H2 with a =1.2295nm and c = 1.2317nm with a possible space group of P6/mmm. This phase exhibits specific orientation relationships with the icosahedral quasicrystal given by [0001]hcx//2/QCand [0110]hex//5/QCwhere 2/qCand 5fQCrepresent twofold and fivefold axes respectively. Electron diffraction patterns from both phases exhibit a close resemblance to the quasicrystalline phase. It is shown that the HI phase is closely related to μ-Al4Mn with the same c parameter while the a parameter is reduced by τ. Following Kreiner and Franzen, it is postulated that both structures (HI and H2) can be understood by a simple hexagonal packing of I13 clusters.

Original languageEnglish
Pages (from-to)1495-1508
Number of pages14
JournalPhilosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
Volume82
Issue number8
DOIs
Publication statusPublished - 2002 May

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Materials Science(all)
  • Condensed Matter Physics
  • Physics and Astronomy (miscellaneous)
  • Metals and Alloys

Cite this