Title
Surface structure of Al-Pd-Mn quasicrystals: Existence of supersaturated bulk vacancy concentrations
Document Type
Article
Publication Date
2003
Journal or Book Title
Physical Review B
Volume
67
Issue
2
First Page
024208
DOI
10.1103/PhysRevB.67.024208
Abstract
We identified the presence and chemical nature of bulk vacancies in Al-Pd-Mn quasicrystals by measuring the structure and composition of two- and fivefold cleavage surfaces of different preannealed quasicrystals subjected to postcleavage heat treatments using scanning electron microscopy and Auger electron spectroscopy. A strong dependence of the surface structure from the preannealing is observed and explained by varying concentrations of bulk vacancies. The analysis of the data shows that as-grown Al-Pd-Mn quasicrystals contain Al, Pd, and Mn vacancies in supersaturated but near stoichiometric concentrations, while long-term preannealed samples contain a much lower vacancy concentration, with a tendency to have excess Al vacancies. We found that Al and Mn vacancies are more mobile at lower temperatures than Pd vacancies, and that the diffusion of Mn vacancies is directly coupled to the mobility of Al vacancies. The results demonstrate that the evolution of the surface structure is primarily affected by bulk vacancies migrating toward the surface during heat treatments and provide a new methodology to characterize the vacancies in intermetallic alloys.
Copyright Owner
American Physical Society
Copyright Date
2003
Language
en
File Format
application/pdf
Recommended Citation
Ebert, Ph.; Yurechko, M.; Kluge, F.; Cai, T.; Grushko, B.; Thiel, Patricia A.; and Urban, K., "Surface structure of Al-Pd-Mn quasicrystals: Existence of supersaturated bulk vacancy concentrations" (2003). Chemistry Publications. 44.
https://lib.dr.iastate.edu/chem_pubs/44
Comments
This article is from Physical Review B 67, no. 2 (2003): 024208, doi:10.1103/PhysRevB.67.024208.