The seeds of Zn6Y8 L12-type clusters in amorphous Mg85Zn6Y9 alloy investigated by photoemission spectroscopy

Abstract

Photoemission and inverse-photoemission spectroscopy (PES and IPES) measurements were carried out on amorphous Mg85Zn6Y9 alloy together with the polycrystal of the same concentrations with a synchronized long-period stacking ordered phase to investigate the valence- and conduction-band electronic structures, respectively. The valence- and conduction-band density of states (DOS) seems to be mostly the same as that of the crystalline phase. The core-level PES measurements were also performed at the Mg 2s, 2p, Zn 3p, 3d, and Y 3d levels to study the chemical natures of the constituent elements. The Y 3d core spectrum exhibits mostly three doublets in the amorphous phase, while mostly only one in the crystalline phase. This result reflects a coexistence of three different sites of the Y atoms in the amorphous phase; ones in the Zn6Y8 L12 clusters or their large fragments of about 57%, ones in their small fragments of about 20%, and isolated atoms of about 23%, which are mostly the same as those in the Mg97Zn1Y2 lightly doped LPSO alloy. Thus, it is concluded that well-fledged seeds of the L12 clusters are already provided even in the amorphous phase.