Chemical interaction and electronic structure in a compositionally complex alloy: A case study by means of X-ray absorption and X-ray photoelectron spectroscopy

JOURNAL OF ALLOYS AND COMPOUNDS

卷:857

Article

Kasatikov, S.^1,2  Fantin, A.^2,3  Manzoni, A. M.^2,4  Sakhonenkov, S.¹  Makarova, A.⁵  Smirnov, D.⁶  Filatova, E. O.¹  Schumacher, G.^2,3 

[1] St Petersburg State Univ, Inst Phys, St Petersburg 198504, Russia

[2] Helmholtz Zentrum Berlin, D-14109 Berlin, Germany

[3] Tech Univ Berlin, D-10623 Berlin, Germany

[4] Bundesanstalt Materialforsch & Prufung, Abt Werkstofftech, D-12205 Berlin, Germany

[5] Tech Univ Dresden, Inst Festkorper & Mat Phys, D-01062 Dresden, Germany

[6] Free Univ Berlin, Inst Chem & Biochem, Phys Chem, D-14195 Berlin, Germany

关键词: High-entropy alloys;    Compositionally complex alloys;    X-ray spectroscopy;    Electronic structure;    Chemical bonding;   

DOI  :  10.1016/j.jallcom.2020.157597

来源: Elsevier

【 摘 要 】

Chemical interaction and changes in local electronic structure of Cr, Fe, Co, Ni and Cu transition metals (TMs) upon formation of an Al8Co17Cr17Cu8Fe17Ni33 compositionally complex alloy (CCA) have been studied by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. It was found that upon CCA formation, occupancy of the Cr, Co and Ni 3d states changes and the maximum of the occupied and empty Ni 3d states density shifts away from Fermi level (E-f) by 0.5 and 0.6 eV, respectively, whereas the Cr 3d empty states maximum shifts towards E-f by 0.3 eV, compared to the corresponding pure metals. The absence of significant charge transfer between the elements was established, pointing to the balancing of the 3d states occupancy change by involvement of delocalized 4s and 4p states into the charge redistribution. Despite the expected formation of strong Al-TMs covalent bonds, the Al role in the transformation of the TMs 3d electronic states is negligible. The work demonstrates a decisive role of Cr in the Ni local electronic structure transformation and suggests formation of directional Ni-Cr bonds with covalent character. These findings can be helpful for tuning deformation properties and phase stability of the CCA. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

Free