X-ray absorption and resonant photoemission spectroscopy of ZrB 2

Abstract

We have performed X-ray absorption and valence band photoemission spectroscopy on ZrB 2, which has the same AlB 2 structure of MgB 2, to study the electronic structure. From X-ray absorption spectra near the B 1s–2p threshold, we found a small absorption edge at 188.23 eV with a negligible angular dependence upto 190 eV photon energy. This indicates that B 2p partial density of states near the Fermi level ( E F) is three dimensional, in sharp contrast to that of MgB 2. Resonant photoemission study across the B 1s–2p threshold was found to be difficult due to a large contribution of Auger electrons. On the other hand, resonant photoemission across the Zr 3p–4d threshold does show small change in intensity within 4 eV of E F. This indicates that the occupied states near E F have substantial Zr 4d character. These observations are in relatively good agreement with band structure calculations.