ELECTRONIC STATES IN GLASSY METALS

Abstract

The key quantity for a characterization of the electronic states of glassy alloys is the density of states. Continued efforts in valence band photoelectron spectroscopy combined with theoretical calculations have advanced our knowledge on occupied electronic states in glassy metals considerably. Research on empty electronic states has recently been started employing the less well known technique of soft x-ray appearance potential spectroscopy (SXAPS) which accesses only states above the Fermi level. SXAPS involves core level excitation and is therefore a local probe, which samples the density of empty states in the environment of a particular alloy constituent. From a comparison of spectra for metallic copper and copper in CuZr a hybridization model will be introduced which provides a consistent interpretation of valence and conduction band states in 3d-zirconium glassy alloys. It will finally be shown that less prominent features in the spectra of pure 3d transition metals are uniquely related to crystallographic order and can be used as fingerprints in the interpretation of corresponding features in alloy spectra. Application to 3d-metal-metalloid glasses indentifies fcc-like short range order at appropriate metalloid concentrations.