Materials, Vol. 16, Pages 1486: Compositionally Complex Alloys: Some Insights from Photoemission Spectroscopy

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Materials, Vol. 16, Pages 1486: Compositionally Complex Alloys: Some Insights from Photoemission Spectroscopy

Materials doi: 10.3390/ma16041486

Authors: Petar Pervan Vesna Mikšić Trontl Ignacio Alejandro Figueroa Tonica Valla Ivo Pletikosić Emil Babić

Photoemission spectroscopy (PES) is an underrepresented part of current and past studies of compositionally complex alloys (CCA) such as high-entropy alloys (HEA) and their derivatives. PES studies are very important for understanding the electronic structure of materials, and are therefore essential in some cases for a correct description of the intrinsic properties of CCAs. Here, we present several examples showing the importance of PES. First, we show how the difference between the split-band structure and the common-band structure of the valence band (VB), observed by PES, can explain a range of properties of CCAs and alloys in general. A simple description of the band crossing in CCAs composed from the early and late transition metals showing a split band is discussed. We also demonstrate how a high-accuracy PES study can determine the variation in the density of states at the Fermi level as a function of Cu content in Ti-Zr-Nb-Ni-Cu metallic glasses. Finally, the first results of an attempt to single out the contributions of particular constituents in Cantor-type alloys to their VBs are presented. The basic principles of PES, the techniques employed in studies presented, and some issues associated with PES measurements are also described.

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