Abstract
Magnetic Compton scattering, x-ray magnetic circular dichroism spectroscopy, and bulk magnetometry measurements are performed on a set of medium- (NiFeCo and NiFeCoCr) and high-entropy (NiFeCoCrPd and NiFeCoCrMn) Cantor-Wu alloys. The bulk spin momentum densities determined by magnetic Compton scattering are remarkably isotropic, and this is a consequence of the smearing of the electronic structure by disorder scattering of the electron quasiparticles. Nonzero x-ray magnetic circular dichroism signals are observed for every element in every alloy indicating differences in the populations of the majority and minority spin states implying finite magnetic moments. When Cr is included in the solid solution, the Cr spin moment is unambiguously antiparallel to the total magnetic moment, while a vanishingly small magnetic moment is observed for Mn, despite calculations indicating a large moment. Some significant discrepancies are observed between the experimental bulk and surface magnetic moments. Despite the lack of quantitative agreement, the element-specific surface magnetic moments seem to be qualitatively reasonable.
Original language | English |
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Article number | 174405 |
Journal | Physical Review B |
Volume | 102 |
Issue number | 17 |
DOIs | |
State | Published - Nov 5 2020 |
Funding
The magnetic Compton scattering and soft x-ray absorption spectroscopy experiments were performed with the approval of the Japan Synchrotron Radiation Research Institute (JASRI), Proposals No. 2016B0131 and No. 2017B1243, respectively. D.A.L. gratefully acknowledges the financial support of the National Secretariat of Higher Education, Science, Technology and Innovation of Ecuador (SENESCYT). S.M., G.D.S., and G.M.S. acknowledge funding support by the Energy Dissipation and Defect Evolution (EDDE), an Energy Frontier Research Center funded by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences under Contract No. DE-AC05-00OR22725. We gratefully acknowledge the financial support of the UK EPSRC (Grants No. EP/R029962/1, No. EP/L015544/1, and No. EP/S016465/1).