First Results on the Electronic Distributions of Zn-Mg-Y Alloys as Investigated by Soft X-ray Spectroscopies
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First results on the electronic distributions of Zn-Mg-Y alloys as investigated by soft X-ray spectroscopies Belin-Ferré Esther1, Fournée Vincent1, Sadoc Anne2, Fontaine Marie Françoise1, Dankhazi Zoltan3, Müller Herbert4 and Tsai An Pang5. 1-LCPMR, UMR 7614, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France. 2-LPMS, Université de Cergy-Pontoise, 95031 Cergy-Pontoise Cedex, France and LURE, Bat. 209 D, Centre Universitaire Paris Sud, BP 34, 91898 Orsay Cedex France. 3-Institute for Solid State Physics, ELTE, Pasmany P. Setany 1/A, 1117 Budapest, Hungary. 4-Institüt für Experimentalphysik, TU-Wien, Wiedner Hauptstrasse 8-10, 1040 Wien, Austria. 5-NRIM, Sengen 1-2-1, Tsukuba 305-0047, Japan. ABSTRACT We report our first results on the electronic structure of icosahedral Zn55Mg35Y10 as compared to hexagonal Zn65Mg28Y7 and to the conventional Zn2Mg alloy. The occupied Mg 3s,d, and Mg 3p on the one hand and empty Mg p, Zn d-s and Y d-s states on the other hand have been investigated using soft X-ray emission and photoabsorption spectroscopy, respectively. The various sub-bands presented for Mg are adjusted in the binding energy scale whereas for the other elements they are plotted in the X-ray transition energy scale. We observe that the metallic character of the samples progressively decreases when going from the pure metals to the icosahedral compound. INTRODUCTION Ternary quasicrystalline compounds are not only Al-based but may also be found in alloys of the Zn-Mg-Metal family [1]. In Al-based quasicrystals and crystalline counterparts, the electronic structure was studied by theoretical as well as experimental means. This showed, in particular, the formation of a pseudo-gap at the Fermi level (EF), which is more marked in the quasi-crystal than in the related crystals due to both the Hume-Rothery mechanism and the sp-d hybridisation at EF [2 and references therein]. To the best of our knowledge, no such wide analysis has been done yet for the alloys of the Zn-Mg system. It is well known that the investigation of the electronic structure of a solid can be achieved experimentally thanks to many techniques among which are the X-ray spectroscopies [3,4]. These techniques provide direct insight into the various electronic distributions in the sample and the interactions between their constituents. Hence, we have used them to probe an icosahedral Mg-Zn-Y phase, an approximant of hexagonal structure and conventional Mg2Zn. In the next section of this paper, we recall the underlying principles of the technique used and we give some details on the experimental procedure. Then comes a section, which reports and discusses our data; the last section is a conclusion on these first results. EXPERIMENTALS One of the routes for the recombination of a hole in a core-level of an atom in a solid is the emission of an X-ray photon. Furthermore, a core electron can be promoted to an empty energy level upon absorption of incoming photons. Note that both processes leave a remaining hole in K9.18.1
the outermost occupied band (OB
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