| AVS 55th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS+NC-MoM |
| Session: | Catalysis and Alloy Formation |
| Presenter: | B. Unal, Ames Laboratory and Iowa State University |
| Authors: | B. Unal, Ames Laboratory and Iowa State University T. Duguet, Ecole des Mines, France D. Jing, Ames Laboratory and Iowa State University C.J. Jenks, Ames Laboratory P.C. Canfield, Iowa State University V. Fournee, Ecole des Mines, France P.A. Thiel, Ames Laboratory and Iowa State University |
| Correspondent: | Click to Email |
Quasicrystals are well ordered, but not periodic solid materials which have peculiar surface properties such as low friction and high oxidation resistance. Using a variable temperature scanning tunneling microscope (VT-STM), for the first time, we have studied the (00001) clean twofold surface of a decagonal Al-Cu-Co quasicrystal. Our STM studies have showed that annealing at ca.1000K causes the formation of two different surface phases one of which has a periodic structure while the other is aperiodic. At room temperature, we have also investigated the growth of Ag on these two different surface domains. In the aperiodic one, Ag prefers to segregate into highly anisotropic islands whose longer edges are parallel to the periodic axis (i.e. the tenfold axis). As the total coverage increases, Ag islands grow vertically while preserving their highly anisotropic shape. In the other (periodic) domain, we observe smoother, more conventional growth. These two different growth behaviors strongly indicate that the aperiodic nature of the surface has a strong effect on the growth kinetics.