Mg 2p shallow core-level and local atomic structure of i-ZnMgRE quasicrystals

We present a detailed analysis of theMg 2p shallowcore-levelsmeasured on icosahedral single-grainZnMgY,ZnMgHo, andZnMgEr quasicrystals during a photoelectron microscopy study. The synchrotron radiation photoemission measurements were performed on in situ cleaved samples at a pressure of 10 10 mbar and at lowtemperature, typically 90–150 K. TheMg 2p photoemission lines are essentially broadened as compared to those of theMg 2p spin–orbit doublet recorded on the Zn2Mgcrystalline Laves phase. The broadening is associated to the coordination shifts of theMg 2p level due to the inequivalent magnesium sites in the quasicrystalline lattice. The coordination shifts are calculated on the basis of i-ZnMg(Ho, Y) atomic structure data, recently determined from the pair distribution function analysis. The coordination shifts obtained are up to 0.2 eV. The Mg 2p experimental spectral intensity is nicely reproduced by a superposition of coordination-shifted Mg 2p spin–orbit doublets