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arxiv: 2511.11260 · v1 · submitted 2025-11-14 · ❄️ cond-mat.mtrl-sci

Electronic and magnetic properties of light rare-earth cubic Laves compounds derived from XMCD experiments

Pith reviewed 2026-05-17 22:34 UTC · model grok-4.3

classification ❄️ cond-mat.mtrl-sci
keywords Laves phasesXMCDrare-earth magnetismmixed valenceceriumnickel momentcrystal field effects3d transition metals
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0 comments X

The pith

XMCD experiments detect a finite magnetic moment on nickel in light rare-earth Laves phases.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper examines element-specific electronic and magnetic properties in cubic Laves phases such as NdCo2, PrCo2, CeCo2 and their nickel-containing variants using soft x-ray absorption and XMCD. It establishes that nickel carries a small but finite magnetic moment, which contradicts the standard assumption that nickel remains nonmagnetic in these structures. Cerium displays a mixed-valent ground state that combines magnetic 4f1 and nonmagnetic 4f0 parts, with the balance shifting according to the electronegativity of the neighboring 3d metal. Neodymium and praseodymium retain localized 4f configurations whose moments are reduced by crystal field effects yet stay robust under rare-earth substitution. The work stresses that reliable use of XMCD sum rules for 3d metals requires precise knowledge of unoccupied states while spin moments for light rare earths must come from multiplet calculations.

Core claim

In the cubic Laves series Nd1-xPrxCoNi, Ce0.25Pr0.75CoNi and the corresponding binaries, XMCD reveals a finite magnetic moment on nickel atoms. Neodymium and praseodymium maintain localized 4f3 and 4f2 states with moments suppressed relative to free-ion values by crystal field splitting. Cerium instead adopts a tunable mixed-valent configuration whose magnetic 4f1 fraction varies with the electronegativity of the surrounding 3d transition metal.

What carries the argument

X-ray magnetic circular dichroism sum rules applied with careful estimates of unoccupied 3d states, supplemented by crystal-field multiplet calculations for the rare-earth ions.

If this is right

  • Transition-metal moments saturate below 1 T while rare-earth moments remain unsaturated even at 5 T.
  • Neodymium and praseodymium preserve localized 4f configurations whose element-specific moments are insensitive to rare-earth substitution.
  • The relative weight of the magnetic 4f1 component in cerium can be adjusted by changing the electronegativity of the 3d partner metal.
  • Orbital moments follow from the orbital sum rule, but spin moments for light rare earths must be taken from multiplet theory because the spin sum rule fails.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Selecting more electronegative 3d metals could increase the magnetic fraction in cerium-based Laves phases and thereby enhance overall magnetization.
  • The same careful treatment of unoccupied states and multiplet corrections may improve moment extraction in other rare-earth intermetallics where standard sum-rule assumptions break down.
  • Small nickel moments could mediate indirect coupling between rare-earth sites, suggesting new routes to tune ordering temperatures through nickel content.

Load-bearing premise

Extraction of magnetic moments from XMCD requires accurate estimates of unoccupied 3d states for transition metals and single-ion multiplet calculations for light rare-earth spin moments.

What would settle it

An independent determination of the nickel magnetic moment, for instance by polarized neutron diffraction on a single crystal of NdNi2 or PrNi2, would confirm or refute the finite value extracted from the XMCD sum rules.

Figures

Figures reproduced from arXiv: 2511.11260 by Anja O. Sj{\aa}stad, Benedicte S. Ofstad, Bj{\o}rn C. Hauback, Christoph Frommen, {\O}ystein S. Fjellv{\aa}g, Philippe Ohresser, Vilde G. S. Lunde.

Figure 1
Figure 1. Figure 1: FIG. 1: (a) Co and (b) Ni experimental [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2: (a) The orbital (hatched) and spin (filled) moment for Nd, Pr, Co, an [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3: The total Co and Ni moment as a function of the [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4: Field-dependent XMCD measurements performed at 4.2 K, at the [PITH_FULL_IMAGE:figures/full_fig_p007_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5: Normalized field-dependent magnetization curves measured usi [PITH_FULL_IMAGE:figures/full_fig_p007_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: presents the XAS and XMCD spectra of the Ce-edge for Ce0.25Pr0.75CoNi, with the binary samples CeCo2 and CeNi2 included for comparison. Both the M5 and M4 edges consist of multiple peaks. The three most intense M5 peaks are at 884.7, 885.7, and 887.1 eV, and the two most dominant M4 peaks are at 903.0 and 904.7 eV. Both edges contain shoulders at higher and lower energies than the main peaks. Some of the p… view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7: Lineshape analysis of the experimental [PITH_FULL_IMAGE:figures/full_fig_p009_7.png] view at source ↗
read the original abstract

This work presents electronic and magnetic properties of selected members in the cubic Laves phase series Nd1-xPrxCoNi and Ce0.25Pr0.75CoNi, together with the corresponding binary compositions (NdCo2, NdNi2, PrCo2, PrNi2, CeCo2, CeNi2), using soft x-ray absorption spectroscopy, x-ray magnetic circular dichroism (XMCD), density-functional theory, and crystal field multiplet calculations. All transition-metal moments saturate below 1 T, while the rare-earth moments do not saturate even at 5 T, consistent with van Vleck paramagnetic contributions and crystal field suppression. While the sum rules are widely used to extract element-specific magnetic moments from XMCD, we show that for 3d transition metals, their application requires accurate estimates of the number of unoccupied 3d states. We observe a finite magnetic moment on Ni, challenging the common assumption of its nonmagnetic character in Laves phases. The orbital magnetic moments were determined using the spin rules, while the spin moments were estimated from single-ion values from multiplet calculations, due to the invalidity of the spin sum rule for light rare-earth elements. The magnetic moments of Nd and Pr are found to be suppressed relative to their free-ion values, with multiplet theory indicating that this is due to crystal field effects. Our results confirm that Nd and Pr maintain localized 4f3 and 4f2 configurations, respectively, and that their element-specific magnetic moments are robust to rare-earth substitution. Ce, on the other hand, exhibits a tunable mixed-valent ground state with both magnetic 4f1 and nonmagnetic 4f0 components. The relative fraction of these states varies with the electronegativity of the surrounding 3d transition metals, revealing a pathway to tune Ce magnetism via composition. This work establishes a framework for accurately interpreting XMCD in light rare-earth-based intermetallics.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 2 minor

Summary. The manuscript reports XMCD, XAS, DFT, and crystal-field multiplet calculations on cubic Laves-phase compounds Nd1-xPrxCoNi, Ce0.25Pr0.75CoNi and the binaries NdCo2, NdNi2, PrCo2, PrNi2, CeCo2, CeNi2. It finds that all 3d transition-metal moments saturate below 1 T while rare-earth moments do not, extracts a finite Ni moment via sum rules, determines orbital moments from spin rules and spin moments from multiplet calculations for light rare earths, and reports crystal-field suppression of Nd/Pr moments together with a tunable mixed-valent Ce ground state whose 4f1/4f0 fraction varies with 3d-metal electronegativity.

Significance. If the finite Ni moment is shown to be robust against reasonable variations in the unoccupied 3d-hole count, the result would directly challenge the common assumption of non-magnetic Ni in Laves phases and underscore the need for careful sum-rule application in hybridized 3d-4f systems. The demonstration that Ce valence can be tuned by composition provides a concrete route to control magnetism in these intermetallics. The paper correctly notes the invalidity of the spin sum rule for light rare earths and appropriately substitutes single-ion multiplet values; this methodological clarity is a strength.

major comments (1)
  1. Abstract and the Ni L-edge XMCD analysis section: the central claim of a finite magnetic moment on Ni rests on sum-rule extraction at the Ni L2,3 edges. The text correctly states that accurate knowledge of the number of unoccupied 3d states (n_h) is required, yet no numerical value, derivation method (XAS edge jump, DFT, or literature), or sensitivity analysis is supplied. Because both spin and orbital moments scale linearly with n_h, an uncertainty of even 0.2–0.5 holes—plausible given 5d/4f hybridization—can shift the reported moment across zero or render it statistically insignificant. This uncertainty directly affects the load-bearing claim that challenges the non-magnetic character of Ni.
minor comments (2)
  1. The abstract omits error bars on the extracted moments, raw spectra, and quantitative Ce 4f1/4f0 fractions, making it difficult for readers to assess the statistical significance of the reported values.
  2. Notation for the unoccupied-state count (n_h) should be defined explicitly at first use and cross-referenced to the specific equation or table where its value is determined.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the positive evaluation of our work and the insightful comment on the Ni moment extraction. We address the major comment in detail below and will revise the manuscript accordingly.

read point-by-point responses
  1. Referee: Abstract and the Ni L-edge XMCD analysis section: the central claim of a finite magnetic moment on Ni rests on sum-rule extraction at the Ni L2,3 edges. The text correctly states that accurate knowledge of the number of unoccupied 3d states (n_h) is required, yet no numerical value, derivation method (XAS edge jump, DFT, or literature), or sensitivity analysis is supplied. Because both spin and orbital moments scale linearly with n_h, an uncertainty of even 0.2–0.5 holes—plausible given 5d/4f hybridization—can shift the reported moment across zero or render it statistically insignificant. This uncertainty directly affects the load-bearing claim that challenges the non-magnetic character of Ni.

    Authors: We agree that a detailed account of n_h and its uncertainty is essential to substantiate the finite Ni moment. In the revised manuscript, we will specify the value of n_h derived from the XAS edge-jump analysis at the Ni L_{2,3} edges, calibrated against literature values for similar Ni compounds. Additionally, we will include a sensitivity analysis demonstrating that the extracted moment on Ni remains finite and statistically significant for plausible variations in n_h of up to 0.5 holes. This revision will directly address the concern and reinforce the robustness of our claim against the common assumption of non-magnetic Ni in these Laves phases. revision: yes

Circularity Check

0 steps flagged

No significant circularity; derivation remains independent of target claims

full rationale

The paper extracts element-specific moments via standard XMCD sum-rule formulas applied to measured spectra at the Ni L edges and rare-earth M edges. The finite Ni moment follows directly from the XMCD integrals scaled by an external estimate of unoccupied 3d states (n_h), with the paper explicitly noting the requirement for accurate n_h but not deriving n_h from the extracted moments themselves. Light-RE spin moments are taken from independent single-ion multiplet calculations because the spin sum rule is invalid for these ions; orbital moments use the orbital sum rule. No equations reduce the reported moments to fitted parameters or prior self-citations by construction, and no uniqueness theorems or ansatzes are smuggled in. The central claims rest on experimental data and standard analysis tools whose inputs (spectra, n_h estimates, multiplet parameters) are independent of the final moment values.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The analysis rests on the applicability of XMCD sum rules once unoccupied 3d states are correctly estimated, the validity of crystal-field multiplet calculations for estimating spin moments of light rare earths, and standard DFT assumptions for electronic structure; no new entities are postulated.

axioms (2)
  • domain assumption XMCD sum rules for 3d metals can be applied once the number of unoccupied 3d states is accurately known
    Explicitly stated as a requirement for extracting moments from the data.
  • domain assumption Spin sum rule is invalid for light rare-earth elements so spin moments are taken from single-ion multiplet calculations
    Direct justification given for using multiplet theory instead of the sum rule.

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Works this paper leans on

60 extracted references · 60 canonical work pages

  1. [1]

    Franco, J

    V. Franco, J. Bl´ azquez, J. Ipus, J. Law, L. Moreno- Ram ´ ırez, and A. Conde, Magnetocaloric effect: From materials research to refrigeration devices, Progress in Materials Science 93, 112 (2018)

  2. [2]

    Romero-Mu˜ niz, J

    C. Romero-Mu˜ niz, J. Y. Law, J. Revuelta-Losada, L. M. Moreno-Ram ´ ırez, and V. Franco, Magnetocaloric mate- rials for hydrogen liquefaction, The Innovation Materials 1, 100045 (2023). 10

  3. [3]

    P. K. Jesla, J. A. Chelvane, A. V. Morozkin, and R. Nirmala, Large Low Field Magnetocaloric Effect in Multicomponent Laves Phase Intermetallic Compounds Gd0.33Dy0.33Ho0.33Al2 , Tb 0.33Ho0.33Er0.33Al2 , and Dy0.33Ho0.33Er0.33Al2, IEEE Transactions on Magnetics 59, 1 (2023)

  4. [4]

    ´Cwik, Y

    J. ´Cwik, Y. Koshkid’ko, K. Shinde, J. Park, N. A. De Oliveira, M. Babij, and A. Czernuszewicz, Magnetic and magnetocaloric properties of Dy 1-xErxNi2 solid solu- tions and their promise for hydrogen liquefaction, Journal of Materials Chemistry C 12, 14421 (2024)

  5. [5]

    Politova, I

    G. Politova, I. Tereshina, A. Karpenkov, V. Chzhan, and J. Cwik, Magnetism, magnetocaloric and magnetostric- tive effects in RCo 2 – type (R = Tb, Dy, Ho) Laves phase compounds, Journal of Magnetism and Magnetic Mate- rials 591, 171700 (2024)

  6. [6]

    Bykov, A

    E. Bykov, A. Karpenkov, W. Liu, M. Straßheim, T. Niehoff, K. Skokov, F. Scheibel, O. Gutfleisch, C. Salazar Mej ´ ıa, J. Wosnitza, and T. Gottschall, Mag- netocaloric effect in the Laves phases RCo2 (R = Er, Ho, Dy, and Tb) in high magnetic fields, Journal of Alloys and Compounds 977, 173289 (2024)

  7. [7]

    EU, Regulation (EU) 2024/1252 of the European parlia- ment and of the council of 11 April 2024 establishing a framework for ensuring a secure and sustainable supply of critical raw materials (2024)

  8. [8]

    W. Liu, T. Gottschall, F. Scheibel, E. Bykov, A. Aubert, N. Fortunato, B. Beckmann, A. M. D¨ oring, H. Zhang, K. Skokov, and O. Gutfleisch, A matter of performance and criticality: A review of rare-earth-based magne- tocaloric intermetallic compounds for hydrogen lique- faction, Journal of Alloys and Compounds 995, 174612 (2024)

  9. [9]

    Ohresser, N

    P. Ohresser, N. B. Brookes, S. Padovani, F. Scheurer, and H. Bulou, Magnetism of small Fe clusters on Au(111) studied by x-ray magnetic circular dichroism, Physical Review B 64, 104429 (2001)

  10. [10]

    Van Der Laan and A

    G. Van Der Laan and A. I. Figueroa, X-ray magnetic circular dichroism—A versatile tool to study magnetism, Coordination Chemistry Reviews 277-278, 95 (2014)

  11. [11]

    Giorgetti, E

    C. Giorgetti, E. Dartyge, F. Baudelet, and R.-M. Gal´ era, XMCD at the L ii,iii edges of Er in ErMn 2, ErFe2, ErCo 2, ErNi2, and ErAl 2 Laves phases and in Er 2(SO4)3 , 8H 20, Physical Review B 70, 035105 (2004)

  12. [12]

    Mizumaki, K

    M. Mizumaki, K. Yano, I. Umehara, F. Ishikawa, K. Sato, A. Koizumi, N. Sakai, and T. Muro, Verification of Ni magnetic moment in GdNi 2 Laves phase by magnetic circular dichroism measurement, Physical Review B 67, 132404 (2003)

  13. [13]

    Wilhelm, R

    F. Wilhelm, R. Eloirdi, J. Rusz, R. Springell, E. Colin- eau, J.-C. Griveau, P. M. Oppeneer, R. Caciuffo, A. Ro- galev, and G. H. Lander, X-ray magnetic circular dichro- ism experiments and theory of transuranium Laves phase compounds, Physical Review B 88, 024424 (2013)

  14. [14]

    Fujiwara, K

    A. Fujiwara, K. Asakura, I. Harada, H. Ogasawara, and A. Kotani, XMCD Study on Electronic and Magnetic States of RareEarth 5 d Electrons in Laves Compounds, RFe2 (R = Rare-Earth), Physica Scripta , 113 (2005)

  15. [15]

    Bartolom´ e, J

    F. Bartolom´ e, J. Herrero-Albillos, L. Garcı ´ ıa, A. Young, T. Funk, N. Plugaru, and E. Arenholz, Orbital moment at the Curie temperature in ErCo 2, Journal of Magnetism and Magnetic Materials 272-276, 319 (2004)

  16. [16]

    Herrero-Albillos, F

    J. Herrero-Albillos, F. Bartolom´ e, L. M. Garc ´ ıa, A. T. Young, T. Funk, J. Campo, and G. J. Cuello, Observa- tion of a different magnetic disorder in ErCo 2, Physical Review B 76, 094409 (2007)

  17. [17]

    Watanabe, N

    S. Watanabe, N. Ishimatsu, H. Maruyama, J. Chaboy, M. A. Laguna-Marco, R. Boada, and N. Kawamura, Pressure dependence of magnetic states in Laves Phase RCo2 (R = Dy, Ho, and Er) compounds probed by XMCD, Journal of Physics: Conference Series 190, 012021 (2009)

  18. [18]

    Giorgetti, S

    C. Giorgetti, S. Pizzini, E. Dartyge, A. Fontaine, F. Baudelet, C. Brouder, P. Bauer, G. Krill, S. Miraglia, D. Fruchart, and J. P. Kappler, Magnetic circular x-ray dichroism in Ce intermetallic compounds, Physical Re- view B 48, 12732 (1993)

  19. [19]

    Delobbe, A.-M

    A. Delobbe, A.-M. Dias, M. Finazzi, L. Stichauer, J.-P. Kappler, and G. Krill, X-ray magnetic circular dichroism study on CeFe 2, Europhysics Letters 43, 320 (1998)

  20. [20]

    Chaboy, M

    J. Chaboy, M. A. Laguna-Marco, C. Piquer, H. Maruyama, and N. Kawamura, Relationship be- tween XMCD and molecular field in rare-earth (R) transition-metal (T) intermetallic compounds, Journal of Physics: Condensed Matter 19, 436225 (2007)

  21. [21]

    Okane, Y

    T. Okane, Y. Takeda, H. Yamagami, A. Fujimori, Y. Matsumoto, N. Kimura, T. Komatsubara, and H. Aoki, Magnetic behavior near the boundary of 4 f delo- calization in ferromagnetic CeRu 2Ge2 and paramagnetic CeRu2Si2 observed by Ce M 4,5 XAS and XMCD, Physi- cal Review B 86, 125138 (2012)

  22. [22]

    C. T. Chen, Y. U. Idzerda, H.-J. Lin, N. V. Smith, G. Meigs, E. Chaban, G. H. Ho, E. Pellegrin, and F. Sette, Experimental Confirmation of the X-Ray Mag- netic Circular Dichroism Sum Rules for Iron and Cobalt, Physical Review Letters 75, 152 (1995)

  23. [23]

    B. T. Thole, G. Van Der Laan, J. C. Fuggle, G. A. Sawatzky, R. C. Karnatak, and J.-M. Esteva, 3d x-ray- absorption lines and the 3d 9 4f n+1 multiplets of the lan- thanides, Physical Review B 32, 5107 (1985)

  24. [24]

    Carra, B

    P. Carra, B. T. Thole, M. Altarelli, and X. Wang, X- ray circular dichroism and local magnetic fields, Physical Review Letters 70, 694 (1993)

  25. [25]

    Nakajima, J

    R. Nakajima, J. St¨ ohr, and Y. U. Idzerda, Electron-yield saturation effects in L -edge x-ray magnetic circular dichroism spectra of Fe, Co, and Ni, Physical Review B 59, 6421 (1999)

  26. [26]

    J. P. Schill´ e, J. P. Kappler, P. Sainctavit, C. Cartier Dit Moulin, C. Brouder, and G. Krill, Experimental and calculated magnetic dichroism in the Ho 3 d x-ray- absorption spectra of intermetallic HoCo 2, Physical Re- view B 48, 9491 (1993)

  27. [27]

    St¨ ohr and H

    J. St¨ ohr and H. K¨ onig, Determination of Spin- and Orbital-Moment Anisotropies in Transition Metals by Angle-Dependent X-Ray Magnetic Circular Dichroism, Physical Review Letters 75, 3748 (1995)

  28. [28]

    Teramura, A

    Y. Teramura, A. Tanaka, and T. Jo, Effect of Coulomb Interaction on the X-Ray Magnetic Circular Dichroism Spin Sum Rule in 3 d Transition Elements, Journal of the Physical Society of Japan 65, 1053 (1996)

  29. [29]

    Teramura, A

    Y. Teramura, A. Tanaka, and T. Jo, Effect of Coulomb Interaction on the X-Ray Magnetic Circular Dichroism Spin Sum Rule in Rare Earths, Journal of the Physical Society of Japan 65, 3056 (1996)

  30. [30]

    T. Jo, The 3 d –4f exchange interaction, X-ray second- order optical processes and the magnetic circular dichro- 11 ism (MCD) spin sum rule in rare earths, Journal of Electron Spectroscopy and Related Phenomena 86, 73 (1997)

  31. [31]

    V. G. Lunde, A. B. Møller, B. G. Eggert, A. M. D¨ oring, J.-C. Grivel, R. Bjørk, F. Veillon, K. Skokov, O. Gut- fleisch, A. O. Sj ˚ astad, B. C. Hauback, and C. From- men, Machine learning guided discovery and experimen- tal validation of light rare earth Laves phases for mag- netocaloric hydrogen liquefaction, Acta Materialia 297, 121282 (2025)

  32. [32]

    R. E. Dinnebier, A. Leineweber, and J. S. O. Evans, Rietveld refinement practical powder diffraction pattern analysis using topas, Journal of Applied Crystallography 52, 1238 (2019)

  33. [33]

    Ohresser, E

    P. Ohresser, E. Otero, F. Choueikani, K. Chen, S. Stanescu, F. Deschamps, T. Moreno, F. Polack, B. La- garde, J.-P. Daguerre, F. Marteau, F. Scheurer, L. Joly, J.-P. Kappler, B. Muller, O. Bunau, and P. Sainctavit, DEIMOS: A beamline dedicated to dichroism measure- ments in the 350–2500 eV energy range, Review of Sci- entific Instruments 85, 013106 (2014)

  34. [34]

    L. Joly, E. Otero, F. Choueikani, F. Marteau, L. Cha- puis, and P. Ohresser, Fast continuous energy scan with dynamic coupling of the monochromator and undulator at the DEIMOS beamline, Journal of Synchrotron Radi- ation 21, 502 (2014)

  35. [35]

    Kresse and J

    G. Kresse and J. Furthm¨ uller, Efficiency of ab initio total energy calculations for metals and semiconductors using a plane-wave basis set, Computational Materials Science 6, 15 (1996)

  36. [36]

    Kresse and J

    G. Kresse and J. Hafner, Ab initio molecular dynamics for liquid metals, Physical Review B 47, 558 (1993), pub- lisher: American Physical Society

  37. [37]

    Kresse and J

    G. Kresse and J. Furthm¨ uller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Physical Review B 54, 11169 (1996), publisher: American Physical Society

  38. [38]

    Mejia-Rodriguez and S

    D. Mejia-Rodriguez and S. B. Trickey, Deorbitalized meta-GGA exchange-correlation functionals in solids, Physical Review B 98, 115161 (2018)

  39. [39]

    H. J. Monkhorst and J. D. Pack, Special points for Brillouin-zone integrations, Physical Review B 13, 5188 (1976), publisher: American Physical Society

  40. [40]

    Cococcioni and S

    M. Cococcioni and S. de Gironcoli, Linear response ap- proach to the calculation of the effective interaction pa- rameters in the LDA+U method, Physical Review B 71, 035105 (2005), publisher: American Physical Society

  41. [41]

    M. W. Haverkort, G. Sangiovanni, P. Hansmann, A. Toschi, Y. Lu, and S. Macke, Bands, resonances, edge singularities and excitons in core level spectroscopy in- vestigated within the dynamical mean-field theory, Eu- rophysics Letters 108, 57004 (2014), publisher: EDP Sci- ences, IOP Publishing and Societ` a Italiana di Fisica

  42. [42]

    R. D. Cowan, Theoretical Calculation of Atomic Spectra Using Digital Computers*, JOSA 58, 808 (1968)

  43. [43]

    See Supplemental Material [url] for detailed methodol- ogy of multiplet theory simulations, Rietveld refinements of XRD data, additional XMCD and XAS spectra and hysteresis curves, and tabulated magnetic moments from sum rules and simulations

  44. [44]

    J. B. Goedkoop, B. T. Thole, G. Van Der Laan, G. A. Sawatzky, F. M. F. De Groot, and J. C. Fuggle, Calcu- lations of magnetic x-ray dichroism in the 3 d absorption spectra of rare-earth compounds, Physical Review B 37, 2086 (1988)

  45. [45]

    G. V. D. Laan, B. T. Thole, G. A. Sawatzky, J. C. Fuggle, and R. Karnatak, Identification of the relative population of spin-orbit split states in the ground state of a solid, Journal of Physics C: Solid State Physics 19, 817 (1986)

  46. [46]

    Farrell and W

    J. Farrell and W. E. Wallace, Magnetic Properties of Intermetallic Compounds between the Lanthanides and Nickel or Cobalt, Inorganic Chemistry 5, 105 (1966)

  47. [47]

    Wallace and K

    W. Wallace and K. Mader, Magnetic characteristics of PrzY1− zNi2 alloys and the nature of PrNi 2 at low tem- peratures, Inorganic Chemistry 7, 1627 (1968)

  48. [48]

    ´Avila Guti´ errez, A

    M. ´Avila Guti´ errez, A. Moisset, A.-T. Ngo, S. Costanzo, G. Simon, P. Colomban, M. Petit, C. Petit, and I. Lisiecki, Influence of the nanocrystallinity on exchange bias in Co/CoO core/shell nanoparticles, Colloids and Surfaces A: Physicochemical and Engineering Aspects 676, 132281 (2023)

  49. [49]

    Blundell, Magnetism in condensed matter , Oxford master series in condensed matter physics (Oxford Uni- versity Press, Oxford ; New York, 2001)

    S. Blundell, Magnetism in condensed matter , Oxford master series in condensed matter physics (Oxford Uni- versity Press, Oxford ; New York, 2001)

  50. [50]

    Ermolenko, A

    A. Ermolenko, A. Korolev, E. Gerasimov, V. Gaviko, P. Terentev, and N. Mushnikov, Compositional genesis of ferromagnetism in alloys PrNi 2-xCox, Journal of Mag- netism and Magnetic Materials 490, 165489 (2019)

  51. [51]

    Y. G. Xiao, Q. Huang, Z. W. Ouyang, F. W. Wang, J. W. Lynn, J. K. Liang, and G. H. Rao, Canted magnetic structure arising from rare-earth mixing in the Laves- phase compound (Nd 0.5Tb0.5)Co2, Physical Review B 73, 064413 (2006)

  52. [52]

    B. K. Rai, A. D. Christianson, G. Sala, M. B. Stone, Y. Liu, and A. F. May, Magnetism of Nd 2O3 single crys- tals near the N´ eel temperature, Physical Review B 102, 054434 (2020)

  53. [53]

    Hinatsu and T

    Y. Hinatsu and T. Fujino, Magnetic susceptibilities of UO2-Pr2O3 solid solutions, Journal of Solid State Chem- istry 74, 163 (1988)

  54. [54]

    Roth, The magnetic structure of Co 3O4, Journal of Physics and Chemistry of Solids 25, 1 (1964)

    W. Roth, The magnetic structure of Co 3O4, Journal of Physics and Chemistry of Solids 25, 1 (1964)

  55. [55]

    Mandziak, G

    A. Mandziak, G. D. Soria, J. E. Prieto, P. Pri- eto, C. Granados-Miralles, A. Quesada, M. Foerster, L. Aballe, and J. de la Figuera, Tuning the N´ eel tem- perature in an antiferromagnet: the case of Ni xCo1-xO microstructures, Scientific Reports 9, 13584 (2019)

  56. [56]

    Melcher, S

    C. Melcher, S. Friedrich, S. Cramer, M. Spurrier, P. Szupryczynski, and R. Nutt, Cerium oxidation state in LSO:Ce scintillators, IEEE Transactions on Nuclear Science 52, 1809 (2005)

  57. [57]

    H. B. Vasili, B. Casals, R. Cichelero, F. Maci` a, J. Geshe v, P. Gargiani, M. Valvidares, J. Herrero-Martin, E. Pelle- grin, J. Fontcuberta, and G. Herranz, Direct observation of multivalent states and 4 f → 3d charge transfer in Ce- doped yttrium iron garnet thin films, Physical Review B 96, 014433 (2017)

  58. [58]

    W. Liu, T. Gottschall, F. Scheibel, E. Bykov, N. For- tunato, A. Aubert, H. Zhang, K. Skokov, and O. Gut- fleisch, Designing magnetocaloric materials for hydrogen liquefaction with light rare-earth Laves phases, Journal of Physics: Energy 5, 034001 (2023)

  59. [59]

    V. G. S. Lunde, Data for LIQUID-H (2025), data- verseNO, doi: 10.18710/PT4R3F. Supplemental material for ”Electronic and magnetic properties of ligh t rare-earth cubic Laves compounds derived from XMCD experiments” Vilde G. S. Lunde, 1, ∗ Benedicte S. Ofstad, 1 Øystein S. Fjellv ˚ ag,1 Philippe Ohresser,2 Anja O. Sj ˚ astad,3 Bjørn C. Hauback, 1 and Chris...

  60. [60]

    Thus, is A0 4 the only free parameter for Ce

    On the other hand, Ce has J = 5/ 2 and the expansion coefficients Al m can only act on a multiplet with m larger than 2 J. Thus, is A0 4 the only free parameter for Ce. The correct crystal field parameters we re identified by restricting the model to the XMCD spectra and the orbital moment , as determined by the orbital sum rules. As one or two parameters des...