Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-17T14:51:52.075Z Has data issue: false hasContentIssue false

Atom Clusters In A 2/1 Cubic Approximant Phase For Understanding The Structures Of Icosahedral Phases

Published online by Cambridge University Press:  10 February 2011

K. HIRAGA*
Affiliation:
Institute for Materials Research, Tohoku University, Sendai 980–8577,Japan, [email protected]
Get access

Abstract

Two types of atom clusters found in the β-(A1PdMnSi) cubic phase, referred to as a 2/1 crystalline approximant, with a composition of approximately Al70Pd23Mn6Si1 which is near to the composition Al72Pd20Mn8 of the icosahedral phase, are discussed in detail for understanding the structure of the Al-Pd-Mn icosahedral phase. A large dodecahedral atom cluster located at the body-centered position can be divided into 19 atom shells with approximately icosahedral symmetry, and a dodecahedron of the 12th shell internally touches the surface of the cubic unit cell with a lattice constant of 2.0211 nm. At each vertex of the dodecahedron, a small icosahedral atom cluster consisting of 12 Al atoms surrounding a central Pd atom is located. The dodecahedron is connected to each other by edge-sharing, namely by sharing two small icosahedral atom clusters, along the twofold rotational direction, and forms a simple-cubic packing of the atom cluster in the β-(AlPdMnSi) cubic phase. Another atom cluster located at the origin fills up gaps of the simple-cubic packing of the large dodecahedral atom cluster. By using the dodecahedral and bridging atom clusters, the structure of the Al-Pd-Mn icosahedral quasicrystal is discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Hiraga, K., in Advances in Imaging and Electron Physics, 101, edited by Hawkes, P. W. (Academic Press, 1998), p. 3798.Google Scholar
2. Hiraga, K. and W. Sun. Phil. Mag. Lett. 67, 117 (1993).Google Scholar
3. Hiraga, K., Abe, E., and Matsuo, Y., Phil. Mag. Lett. 70, 163 (1994).Google Scholar
4. Li, X. Z. and Kuo, K. H., Phil. Mag. B 65, 525 (1992).Google Scholar
5. Hiraga, K., Kaneko, M., Matsuo, Y., and Hashimoto, S., B 67, 193 (1993).Google Scholar
6. Matsuo, Y. and Hiraga, K., Phil. Mag. Lett. 70, 155 (1994).Google Scholar
7. Cooper, M. and Robinson, K., ActaCryst. 20, 614 (1966).Google Scholar
8. Sugiyama, K., Kaji, N., and Hiraga, K., Acta Cryst. C 54, 445 (1998).Google Scholar
9. Bergman, G., Waugh, L. T., and Pauling, L., Acta Cryst. 10, 254 (1957).Google Scholar
10. Elser, V. and Henley, C. L., Phys. Rev. Lett. 55, 2883 (1985).Google Scholar
11. Guyot, P. and Audier, M., Phil. Mag. B 52, L15 (1985).Google Scholar
12. Audier, M. and Guyot, P., Phil. Mag. B 53, L43 (1986).Google Scholar
13. Sugiyama, K., Kaji, N., Hiraga, K., and Ishimasa, T., Z. Kristallogr. 213, 168 (1998).Google Scholar
14. Sugiyama, K., Kaji, N., Hiraga, K., and Ishimasa, T., Z. Kristallogr. 213, 90 (1998).Google Scholar
15. Sugiyama, K., Kato, T., Saito, K., and Hiraga, K., Phil. Mag. Lett. 77, 165 (1998).Google Scholar
16. Hiraga, K., Sugiyama, K., and Ohsuna, T., Phil. Mag. 7 8, 1051 (1998).Google Scholar
17. Henley, C. H., Phys. Rev. B 34, 797 (1986).Google Scholar
18. Hiraga, K., Ohsuna, T., and Sugiyama, K., J. Phys. Soc. Jpn. 66, 3700 (1997).Google Scholar
19. Hiraga, K., Lincohn, F. J., and Sun, W., Mater. Trans. JIM, 32, 308 (1991).Google Scholar
20. Hiraga, K., Ohsuna, T., and Sugiyama, K., J. Phys. Soc. Jpn. 67, 1501 (1998).Google Scholar
21. Yamamoto, A. and Hiraga, K., Phys. Rev. B 37, 6207 (1988).Google Scholar