X-ray magnetic circular dichroism in d and f ferromagnetic materials: recent theoretical progress. Part I
The curreThe current status of theoretical understanding of the x-ray magnetic circular dichroism (XMCD) of 4 f and 5 f compounds is reviewed. Energy band theory based upon the local spin-density approximation (LSDA) describes the XMCD spectra of transition metal compounds with high accuracy. Howe...
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Datum: | 2008 |
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Format: | Artikel |
Sprache: | English |
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Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
2008
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Schriftenreihe: | Физика низких температур |
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Online Zugang: | http://dspace.nbuv.gov.ua/handle/123456789/116810 |
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Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
Zitieren: | X-ray magnetic circular dichroism in d and f ferromagnetic materials: recent theoretical progress. Part I / V.N. Antonov, A.P. Shpak, A.N. Yaresko // Физика низких температур. — 2008. — Т. 34, № 2. — С. 107–147. — Бібліогр.: 198 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of UkraineZusammenfassung: | The curreThe current status of theoretical understanding of the x-ray magnetic circular dichroism (XMCD) of 4 f
and 5 f compounds is reviewed. Energy band theory based upon the local spin-density approximation
(LSDA) describes the XMCD spectra of transition metal compounds with high accuracy. However, the
LSDA does not suffice for lanthanide compounds which have a correlated 4 f shell. A satisfactory description
of the XMCD spectra could be obtained by using a generalization of the LSDA, in which explicitly f
electron Coulomb correlation are taken into account (LSDA + U approach). As examples of this group we
consider GdN compound. We also consider uranium 5 f compounds. In those compounds where the 5 f electrons
are rather delocalized, the LSDA describes the XMCD spectra reasonably well. As example of this
group we consider UFe₂. Particular differences occur for the uranium compounds where the 5 f electrons are
neither delocalized nor localized, but more or less semilocalized. Typical examples are UXAl (X = Co, Rh,
and Pt), and UX (X = S, Se, Te). The semilocalized 5 f ’s are, however, not inert, but their interaction with
conduction electrons plays an important role. We also consider the electronic structure and XMCD spectra
of heavy-fermion compounds UPt₃, URu₂Si₂, UPd₂Al3₃, UNi₂Al₃, and UBe₁₃ where the degree of the 5 f localization
is increased in comparison with other uranium compounds. The electronic structure and XMCD
spectra of UGe₂ which possesses simultaneously ferromagnetism and superconductivity also presented. Recently
achieved improvements for describing 5 f compounds are discussed. |
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