THIN-FILM GROWTH OF PT ON CU(111) - A LEIS STUDY

Low energy Li+ ion scattering with a combination of LEED has been used to study thin Pt films on Cu(111) deposited at room temperature (less than or equal to 50 degrees C) and subsequently heated, At room tempe rature, Pt grew epitaxially on Cu(111) in the regular fee stacking seq uence for a thickness of at least five monolayers. For the annealing t emperature of similar to 300 degrees C, Pt-Cu intermixing was observed , forming a metastable Cu3Pt surface alloy. Analysis of the surface la yers was made by analysing the incident angle dependence associated wi th shadowing effects and comparison to the results obtained from a bul k Cu3Pt(111) single crystal, revealing that the alloy is Cu3Pt(111) ph ase over at least three atomic layers, Neither CuPt(111) nor CuPt3(111 ) surface phase has been evidenced in this study.