Electronic structure and magnetism of UCoGe from first principles

Diviš, M.

doi:10.1016/j.physb.2008.01.014

Cited by 21 publications

(48 citation statements)

References 8 publications

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“…The inset of Fig. 6 shows the obtained ρ mag for NpCoGe, which displays a clear maximum around 40 K, as observed in UCoGe and also some other magnetically ordered neptunium-based compounds such as NpCoGa 5 27 or NpNiSi 2 some data point to a low density of carriers in this analogue compound also 24,32 …”

Section: Electrical Resistivity Measurementssupporting

confidence: 54%

Antiferromagnetic ground state in NpCoGe

et al. 2014

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NpCoGe, the neptunium analogue of the ferromagnetic superconductor UCoGe, has been investigated by dcmagnetization, ac-susceptibility, specific heat, electrical resistivity, Hall effect, The comparison with NpRhGe and uranium analogues suggests the leading role of 5f-d hybridization, the rather delocalized character of 5f electrons in NpCoGe and the possible proximity of NpRuGe or NpFeGe to a magnetic quantum critical point.

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Section: Electrical Resistivity Measurementssupporting

confidence: 54%

Antiferromagnetic ground state in NpCoGe

et al. 2014

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“…2. The results are in good agreement with previous band structure calculations [12,[50][51][52][53]. The occupied part of the DOS can be decomposed into two regions.…”

Section: Band Structuresupporting

confidence: 91%

Electronic and magnetic properties of the ferromagnetic superconductor UCoGe

Antonov

2017

Low Temperature Physics

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The electronic structure and x-ray magnetic circular dichroism (XMCD) spectra of the ferromagnetic superconductor UCoGe at the U N 4,5 , Ge and Co K and Co L 2,3 edges were investigated theoretically from first principles, using the fully relativistic Dirac linear muffin-tin orbital band structure method. The electronic structure is obtained with the local spin-density approximation (LSDA), as well as with a generalization of the LSDA+U method which takes into account the non-diagonal occupation matrix (in spin indexes) of localized electrons. A stable ferromagnetic ground state was found. The uranium total magnetic moment is quite small (about -0.171µ B ) in the LSDA approximation as a result of almost complete cancellation between the spin magnetic moment of 0.657 µ B and the opposite orbital magnetic moment of -0.828 µ B , resulting from strong spin-orbit coupling at the uranium site. Valency of U ion in UCoGe is close to 3+. The ratio orbital and spin magnetic moments M l /M s ranged from 1.163 in the GGA approach up to 2.456 for the LSDA+U calculations is smaller than the corresponding ratio for the free ion U 3+ value (2.60), it can indicate a significant delocalization of the 5f-electron states due to the hybridization of the U 5f electrons with the conduction band and Co 3d electrons. The line shape of the dichroic spectra at the U M 5 and M 4 edges predicted by considering the magneto-optical selection rules as well as the occupation and the energy sequence of the m j -projected partial densities of states. The theoretically calculated XMCD spectra at the U M 4,5 , Ge and Co K and Co L 2,3 edges are in good agreement with the experimentally measured spectra. PACS

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“…This is at variance with the electronic-structure calculations. [16][17][18] However, the PND data reveal that the Co moment is susceptible to a magnetic field, and magnetic moments on both the U and Co atoms, as predicted by the calculations, do occur in applied magnetic field. The small value of the Co moment in weak magnetic fields is in line with recent zero-field SR ͑Ref.…”

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confidence: 85%

“…In addition, a much larger moment Co ϳ 0.2-0.5 B is predicted at the Co atom. The magnetic moments on the U and Co sites are expected to orient parallel 16,18 or antiparallel 17 and consequently it is argued that the magnetic structure is quite complex and, for instance, magnetic stripe order 16 or an antiferromagnetic spin arrangement 17 have been proposed. In this Rapid Communication we report PND experiments on UCoGe conducted to identify the different contributions to the bulk magnetization in the normal phase ͓we apply a field B ʈ c larger than the upper critical field B c2 c Ӎ 0.5 T ͑Ref.…”

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confidence: 99%

Anomalous spin distribution in the superconducting ferromagnet UCoGe studied by polarized neutron diffraction

et al. 2010

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Anomalous spin distribution in the superconducting ferromagnet UCoGe studied by polarized neutron diffraction Prokeš, K.; de Visser, A.; Huang, Y.; Fåk, B.; Ressouche, E. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. We report a polarized neutron-diffraction study conducted to reveal the nature of the weak ferromagnetic moment in the superconducting ferromagnet UCoGe. We find that the ordered moment in the normal phase in low magnetic fields ͑B ʈ c͒ is predominantly located at the U atom and has a magnitude of ϳ0.1 B at 3 T, in agreement with bulk magnetization data. By increasing the magnetic field the U moment grows to ϳ0.3 B in 12 T and most remarkably, induces a substantial moment ͑ϳ0.2 B ͒ on the Co atom directed antiparallel to the U moment. The anomalous polarizability of the Co 3d orbitals is unique among uranium intermetallics and might reflect the proximity to a magnetic quantum critical point of UCoGe in zero field.

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Electronic structure and magnetism of UCoGe from first principles

Cited by 21 publications

References 8 publications

Antiferromagnetic ground state in NpCoGe

Antiferromagnetic ground state in NpCoGe

Electronic and magnetic properties of the ferromagnetic superconductor UCoGe

Anomalous spin distribution in the superconducting ferromagnet UCoGe studied by polarized neutron diffraction

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