TY - JOUR

T1 - Chemical interaction and electronic structure in a compositionally complex alloy: A case study by means of X-ray absorption and X-ray photoelectron spectroscopy

AU - Касатиков, Сергей Алексеевич

AU - Fantin, Andrea

AU - Manzoni, Anna

AU - Сахоненков, Сергей Сергеевич

AU - Makarova, Anna

AU - Smirnov, Dmitry

AU - Филатова, Елена Олеговна

AU - Schumacher, Gerhard

N1 - Publisher Copyright: © 2020 Elsevier B.V.

PY - 2021/3/15

Y1 - 2021/3/15

N2 - Chemical interaction and changes in local electronic structure of Cr, Fe, Co, Ni and Cu transition metals (TMs) upon formation of an Al 8Co 17Cr 17Cu 8Fe 17Ni 33 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.

AB - Chemical interaction and changes in local electronic structure of Cr, Fe, Co, Ni and Cu transition metals (TMs) upon formation of an Al 8Co 17Cr 17Cu 8Fe 17Ni 33 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.

KW - Chemical bonding

KW - Compositionally complex alloys

KW - Electronic structure

KW - High-entropy alloys

KW - X-ray spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85095848445&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/279904ae-4066-366a-afcd-3d970648766f/

U2 - 10.1016/j.jallcom.2020.157597

DO - 10.1016/j.jallcom.2020.157597

M3 - Article

VL - 857

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

SN - 0925-8388

M1 - 157597

ER -