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XPS spectra, electronic structure, and magnetic properties of RFe5Al7 intermetallics
The results of X-ray photoelectron spectroscopy measurements (core levels and valence bands) of RFe5Al7 (R = Lu, Tm, Er, Ho, Dy, Tb, Gd) single crystals are presented in comparison with the results of bulk magnetization studies and electronic structure calculations. It is shown that the increase of...
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Published in: | Journal of alloys and compounds 2018-02, Vol.733, p.82-90 |
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Main Authors: | , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | The results of X-ray photoelectron spectroscopy measurements (core levels and valence bands) of RFe5Al7 (R = Lu, Tm, Er, Ho, Dy, Tb, Gd) single crystals are presented in comparison with the results of bulk magnetization studies and electronic structure calculations. It is shown that the increase of the Curie temperature in RFe5Al7 from Tm to Gd is associated with an increase of the indirect R 4f – Fe 3d exchange interaction at the expense of the multiplicity 2S + 1 (statistical weight) in the ground state 2S+1LJ of R3+ ions. The nonmonotonic behavior of the ferrimagnetic compensation temperature, Tcomp, as well as the values of the spontaneous magnetic moment, Ms, and formation energy, Eform, of the 4fn levels in R metals in a series from ErFe5Al7 to GdFe5Al7 are explained by the difference in the quantum numbers L, J and S of the ground state of R3+ ions, leading to a maximum value of Tcomp, Ms and Eform for the Dy-containing compound. The electronic structure of Gd/LuFe5Al7 is calculated using the GGA+U approach, on the basis of which the physical mechanism and relative strength of the interatomic R-Fe and Al-Fe interactions are considered, and also the difference in the magnetic moments of iron atoms in different structural positions is explained.
•The electronic structure of GdFe5Al7 and LuFe5Al7 is calculated in the LSDA+U approach.•The physical mechanism and relative strength of R-Fe and Al-Fe interactions is proposed.•The difference of the magnetic moments of Fe-atoms in different structural positions is explained. |
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ISSN: | 0925-8388 1873-4669 |
DOI: | 10.1016/j.jallcom.2017.10.294 |