ELECTRONIC-STRUCTURE OF AMORPHOUS FE-ZR ALLOYS

Ultraviolet and X-ray photoelectron spectroscopy measurements on amorp hous FexZr100-x films prepared in situ by electron beam co-evaporation are reported. The use of the vapour quenching technique offers the ad vantage of obtaining amorphous samples over an extended concentration range (22 less-than-or-equal-to x less-than-or-equal-to 82) and, most importantly, avoids the extensive sputter cleaning procedure standardl y applied for ex situ prepared samples. For the first time, valence ba nd spectra of amorphous transition metal alloys can be compared direct ly with theoretical photoelectron distribution curves calculated on th e basis of a disordered atomic structure. Predicted variations of the valence band shape are found to be in qualitatively good agreement wit h the experimental data, further supporting the theoretical descriptio n of these amorphous transition metal alloys. Lineshape analysis of th e Fe 2P3/2 core levels reveals an increasing asymmetry with increasing Fe content, a behaviour which can qualitatively be understood in term s of a growing exchange-splitting of the spin-up and spin-down subband s.