The Fermi surface of ordered and disordered Cu3Au as determined by angle resolved photoemission

Full text: Cu3Au is an interesting material which has been studied extensively for its alloying properties, its structural properties and for the bulk and surface order-disorder transition it displays. We have shown previously that it is possible to accurately map the Fermi surface of Cu using photoemission spectroscopy. We present in this paper the bulk Fermi surfaces of the ordered and disordered phases of Cu3Au which have been experimentally mapped using angle resolved constant initial state photoemission spectroscopy. The shape of the Fermi cross-section determined for the disordered phase has been found to be well described by a rigid band model. Comparison to previously reported de Haas-van Alphen results on the ordered phase has found that the neck radius is the same as the value determined for the disordered phase to within experimental error. It has been found however, that the Fermi surface belly radius of the disordered phase is ∼ 20-30% larger than the corresponding calculated distance of the ordered material