Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10653144 | Solid State Communications | 2005 | 6 Pages |
Abstract
We present new electron energy-loss spectroscopy (EELS) and Auger (AES) experiments aimed to study the structural transition of the Ge(111) surface taking place at high temperatures. Our advanced high-temperature set-up allowed us to collect accurate EELS spectra near the M2,3 excitation edges and AES MMV and MVV spectra, corresponding to different probing depths ranging from 4 to 10Â Ã
. The metallization of the surface has been clearly detected by the shift of the M2,3 edge and of the MMV, MVV Auger energies. A detailed study of the transition has been performed using a fine temperature step under thermal equilibrium conditions. The AES and EELS experiments show that a sudden semiconductor-metal transition takes place at about 1000Â K involving mainly the topmost layers. Deeper layers within 10Â Ã
are also involved in the metallization process (in a range of 10 above 1010Â K) and a smooth change in the topmost layers is also observed at higher temperatures up to 1070Â K. These transitions are not fully reversible upon cooling (down to 870Â K). Structural and electronic characteristics of the surface transition are discussed in light of available models.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
A. Di Cicco, B. Giovenali, R. Gunnella, E. Principi, S. Simonucci,