Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5348442 | Applied Surface Science | 2015 | 5 Pages |
Abstract
The growth of Cu on Ag(1Â 1Â 1) under varied growth conditions was investigated with angle-resolved photoemission spectra. The evolution of Cu/Ag(1Â 1Â 1) during annealing was characterized on monitoring its surface states. The surface morphology of a Cu film on Ag(1Â 1Â 1) depends on the temperature and the Cu coverage. Islands or crystalline films develop when Cu is deposited at â¼300Â K. Defects in the Cu films penetrate deeply into the Ag(1Â 1Â 1) substrate and expose the Ag(1Â 1Â 1) surface. The deposition of Cu at a low temperature results in disordered films. On annealing, the films become ordered with defects. Our results show the segregation of Ag on the Cu surface, which occurs at 300Â K and becomes accelerated significantly at â¼380Â K. After being annealed above 430Â K, all islands and films of Cu are fully covered with Ag, showing a (9Â ÃÂ 9) reconstruction. Our results indicate also that the segregation of Ag on the Cu surface occurs only after the Ag(1Â 1Â 1) surface is exposed, indicating that Ag atoms migrate to the Cu(1Â 1Â 1) surface, not through bulk Cu, but along the walls of the islands and the defects in the films.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Dah-An Luh, Chih-Hao Huang, Cheng-Maw Cheng, Ku-Ding Tsuei,