Intermediate-valence behavior in U2Rh2Sb
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arXiv
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| Auteurs principaux: | , , , , , , , , , , , |
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| Format: | Preprint |
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2025
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| _version_ | 1866912482663071744 |
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| author | Legut, D. Krnel, M. Koželj, P. Prots, Yu. Juckel, M. Burkhardt, U. Ormeci, A. Grin, Yu. Leithe-Jasper, A. Kolorenč, J. Svanidze, E. Wdowik, U. D. |
| author_facet | Legut, D. Krnel, M. Koželj, P. Prots, Yu. Juckel, M. Burkhardt, U. Ormeci, A. Grin, Yu. Leithe-Jasper, A. Kolorenč, J. Svanidze, E. Wdowik, U. D. |
| contents | Intermediate-valence behavior is sometimes observed in lanthanide-based materials containing Ce, Yb, Sm or Eu. However, the number of actinide-based systems that exhibit this type of behavior is rather limited. In this work, we present the discovery and characterization of a uranium compound U2Rh2Sb, which turns out to be a candidate for the intermediate-valencebehavior. The material shows a characteristic feature in the magnetic susceptibility around T = 50 K, which can be described within the interconfiguration-fluctuation model of intermediate valence systems. We find the energy difference between the 5f3(U3+) and 5f2(U4+) states to be $δ$Eex/kB $\approx$ 400 K and the corresponding valence fluctuation temperature to be Tvf $\approx$ 140 K. The value of the electronic specific heat coefficient $γ$ = 50 mJ mol-1 U K-2 signals a modest electron effective mass enhancement. The electrical resistivity indicates metallic behavior, albeit with a small residual resistivity ratio. Measurements of thermoelectric properties indicate a change of sign in the Seebeck coefficient around T = 100 K, with a minimum achieved at T = 50 K, which coincides with the broad peak observed in magnetic susceptibility. The experimental results are compared with the theoretical analysis, based on the first-principles calculations, including lattice dynamics. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2507_10720 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Intermediate-valence behavior in U2Rh2Sb Legut, D. Krnel, M. Koželj, P. Prots, Yu. Juckel, M. Burkhardt, U. Ormeci, A. Grin, Yu. Leithe-Jasper, A. Kolorenč, J. Svanidze, E. Wdowik, U. D. Strongly Correlated Electrons Materials Science Intermediate-valence behavior is sometimes observed in lanthanide-based materials containing Ce, Yb, Sm or Eu. However, the number of actinide-based systems that exhibit this type of behavior is rather limited. In this work, we present the discovery and characterization of a uranium compound U2Rh2Sb, which turns out to be a candidate for the intermediate-valencebehavior. The material shows a characteristic feature in the magnetic susceptibility around T = 50 K, which can be described within the interconfiguration-fluctuation model of intermediate valence systems. We find the energy difference between the 5f3(U3+) and 5f2(U4+) states to be $δ$Eex/kB $\approx$ 400 K and the corresponding valence fluctuation temperature to be Tvf $\approx$ 140 K. The value of the electronic specific heat coefficient $γ$ = 50 mJ mol-1 U K-2 signals a modest electron effective mass enhancement. The electrical resistivity indicates metallic behavior, albeit with a small residual resistivity ratio. Measurements of thermoelectric properties indicate a change of sign in the Seebeck coefficient around T = 100 K, with a minimum achieved at T = 50 K, which coincides with the broad peak observed in magnetic susceptibility. The experimental results are compared with the theoretical analysis, based on the first-principles calculations, including lattice dynamics. |
| title | Intermediate-valence behavior in U2Rh2Sb |
| topic | Strongly Correlated Electrons Materials Science |
| url | https://arxiv.org/abs/2507.10720 |