AN EXPERIMENTAL-STUDY OF THE GROWTH OF CO PT(111) BY CORE-LEVEL PHOTOEMISSION SPECTROSCOPY, LOW-ENERGY-ELECTRON DIFFRACTION AND AUGER-ELECTRON SPECTROSCOPY/

We have analysed by use of synchrotron radiation induced angle resolve d photoemission spectroscopy (PES), Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED) the growth of ultrathin Co layers deposited at room temperature on Pt(111) surfaces. The LEED pat terns indicate an incoherent epitaxy and AES data can be explained by a near layer by layer growth mode. Decomposition of the Pt 4f7/2 photo emission line shows characteristic core level shifts for the different environments of Pt atoms, giving insight concerning a relatively shar p interface structure. On the other hand, the Pt/Co interface in the P t/Co/Pt(111) sandwich is less sharp, giving rise to two Pt surface sit es. Annealing of the Co/Pt(111) system at 400-degrees-C gives a surfac e alloy structure with the same symmetry and orientation as the Pt sub strate.