Diffractive and spectroscopic observation of the reversible formation of a surface alloy
1989; Elsevier BV; Volume: 72; Issue: 4 Linguagem: Inglês
10.1016/0038-1098(89)90110-5
ISSN1879-2766
AutoresJ. C. Hansen, M.K. Wagner, James Tobin,
Tópico(s)Surface and Thin Film Phenomena
ResumoPhotoelectron diffraction and photoelectron spectroscopy have been used to observe the changes in the geometrical and electronic structure of Au/Cu(001) caused by the variation of temperature and Au surface concentration. We have followed the formation and elimination of a surface alloy and probed the phase transformation between overlayer and surface alloy. This reversible reaction, in which the Au is first substituted into a Cu surface lattice and then extracted with additional Au, was monitored with the above techniques in an angle-resolving mode, utilizing synchrotron radiation and resonance lamp emission. Our measurements include observing variations in the energies, widths and intensities of the alloy surface state and Au 4f core level, incorporating high resolution binding energy shifts as well as photoelectron diffraction. An almost complete segregation of the Au and Cu is achieved in the deformation of the alloy, despite its reputed stability and strong resemblance to Cu3Au(001).
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