Depletion of the density of states near the Fermi energy induced by disorder and electron correlation in alloys

We have performed high-resolution photoemission study of substitutionally d isordered alloys Cu-Pt, Cu-Ni, and Pd-Pt. The ratios between alloy spectra and pure metal spectra are found to have dips at the Fermi level when the r esidual resistivity is high and when strong repulsive electron-electron int eraction is expected. This is in accordance with Altshuler and Aronov's mod el which predicts a depletion of the density of states at the Fermi level w hen both disorder and electron correlation are present. (C) 2000 published by Elsevier Science Ltd.