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Chemical Disorder And Columnar Vacancies In Ideal Decagonal AL-NI-CO Quasicrystals

Published online by Cambridge University Press:  10 February 2011

Yanfa Yan
Affiliation:
Solid State Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
S. J. Pennycook
Affiliation:
Solid State Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
A.-P. Tsai
Affiliation:
National Research Institute for Metals, Tsukuba, Japan
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Abstruct

Atomic-resolution Z-contrast images provide conclusive evidence for chemical disorder in an ideal Al-Ni-Co quasicrystal. The so-called basic Ni-rich, high-temperature, quasiperiodic structure exhibits chemical disorder at the center of the 2 nm diameter clusters that involves both the Al and Ni(Co) atoms. The atomic structure of the 2 nm clusters is derived directly from the images and differs from previous models. The presence of closely-spaced, half-occupied atomic columns (or columnar vacancies) in specific rings within the clusters is directly observed. We propose that these columnar vacancies mediate the phason flips necessary for transformation to random tiling.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1. Levine, D. and Steinhardt, P. J., Phys. Rev. Lett., 53, 2477 (1984); Phys. Rev. B34, 596 1986; J.E.S.Socolar and P.J.Steinhardt, Phys. Rev. B34, 617 1986; V.Elser, Phys. Rev. Lett. 54, 1730 1985.Google Scholar
2. Henley, C. L., J. Phys. A 21, 1649 (1987); in Quasicrystals: The State of the Art, edited by DiVincenzo, D. P. and Steinhardt, P.J. (World Scientific, Singapore, 1991), p. 429; M.Widom, D.P.Deng, C.L.Henley, Phys. Rev. Lett. 63, 310 1989; K.J.Strandburg, L.Tang, M.V.Jaric, Phys. Rev. Lett.jt 63, 314 1989.Google Scholar
3. Elser, V., Acta Crystallogr. A 42, 36 (1986); T.Janssen, Acta Crystallogr. A 42, 26 1986.Google Scholar
4. Lubensky, T. C., Ramaswamy, S., Toner, J., Phys. Rev. B 32, 7444 (1985).Google Scholar
5. Joseph, D., Ritsch, S., Beeli, C., Phys. Rev. B 55, 8175 (1997).Google Scholar
6. Ritsch, R., Beeli, C., Nissen, H. -U., Godecke, T., Scheffer, M., Luck, R., Phil. Mag. Lett. 74, 99 (1996).Google Scholar
7. Yan, Y., Pennycook, S. J. and Tsai, A. P., Phys. Rev. Lett. 81 (1998) (in press).Google Scholar
8. Pennycook, S. J. and Jesson, D. E., Phys. Rev. Lett. 64, 938 (1990);Google Scholar
9. Jesson, D. E. and Pennycook, S. J., Proc. R. Soc. London Ser. A 449, 273 (1995).Google Scholar
10. Gahler, F. and Roth, J., in Aperiodic '94, edited by Chapuis, G. and Paciorek, W. (World Scientific, Singapore, 1995), p. 183.Google Scholar
11. Yamamoto, A. and Weber, S., Phys. Rev. Lett. 78, 23 (1997).Google Scholar
12. Burkov, S. E., Phys. Rev. Lett. 67, 614 (1991); Phys. Rev. B 47, 12325 1993.Google Scholar
13. Ritsch, S., Nissen, H., Beeli, C., Phys. Rev. Lett. 76, 2507 (1996).Google Scholar
14. Hafner, J., Krajci, M., Mihalkovic, M., Phys. Rev. Lett. 76, 2738 (1996); M. Krajci, J. Hafner, M. Mihalkovic, Phys. Rev. B 56, 3072 (1997).Google Scholar
15. Steurer, W. and Kuo, K. H., Acta Crystallogr. B 46, 703 (1990).Google Scholar
16. Yamamoto, A., Sci. Rep. Res. Inst., Tohoku Univ., A 42 207 (1996).Google Scholar
17. Saitoh, K., Tsuda, K., Tanaka, M., Phil. Mag. A 76, 135 (1997).Google Scholar
18. Saitoh, K., Tsuda, K., Tanaka, M., Kaneko, K., Tsai, A.P., Jpn. J. Appl. Phys. 36, L1400 (1997).Google Scholar