- Tytuł:
- Kondo Lattice Models for Rare-Earth and Actinide Systems
- Autorzy:
- Coqblin, B.
- Tematy:
-
71.27.+a
75.10.Nr
75.30.Nr - Pokaż więcej
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Powiązania:
- https://bibliotekanauki.pl/articles/1426694.pdf Link otwiera się w nowym oknie
- Opis:
- We present here some works on the strong competition between the Kondo effect, magnetic order and eventually spin glass or frustration effect in anomalous rare-earth and actinide systems. First, we develop an underscreened Kondo lattice model with $S_{f}$ = 1 spins for the 5f-electrons and we have recently improved it by deriving, by the Schrieffer-Wolff transformation, a 5f-band with a finite bandwidth. The underscreened Kondo lattice model can account for properties of some uranium and neptunium compounds, like UTe, $Np_2PdGa_3$ or $UCu_2Si_2$ which have a large Curie temperature $T_{c}$ of order 100 K and present also a Kondo behavior. In particular, we can account for the observed maximum of $T_{c}$ under pressure in UTe and the magnetization curves of $NpNiSi_2$ showing the occurrence of the Kondo effect at low temperatures below $T_{c}$. Second, we have studied the properties of disordered cerium alloys like $CeCu_xNi_{1-x}$ or $CeRh_xPd_{1-x}$ by considering the Kondo effect, a ferromagnetic order and a spin glass behavior described by several approaches. The van Hemmen approach gives a good explanation of the properties of cerium alloys and we are describing the magnetic glass clusters which occur in both spin glass and ferromagnetic phases. Third, we present a new description of a frustrated Kondo lattice model, which can account for the behavior under pressure or doping of some ytterbium compounds like $Yb_2Pd_2Sn$ and YbAgGe.
- Dostawca treści:
- Biblioteka Nauki
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