FERMI-SURFACE OF DISORDERED CU3AU AS DETERMINED BY ANGLE-RESOLVED PHOTOEMISSION

The bulk Fermi surface of the disordered phase of Cu,Au has been exper imentally mapped using angle-resolved constant initial-state photoemis sion spectroscopy, The shape of the Fermi cross-section so determined has been found to be well described by a rigid band model. Comparison with previously reported de Haas-van Alphen results of the ordered pha se has shown that the neck radius is unaltered within experimental err or. We find, however, that the Fermi surface belly radius of the disor dered phase is similar to 20-30% larger than the corresponding distanc e as determined by an LMTO calculation for the ordered material.