Role of valence fluctuations in the superconductivity of Ce122 compounds.
Phys Rev Lett
; 113(8): 086403, 2014 Aug 22.
Article
en En
| MEDLINE
| ID: mdl-25192112
ABSTRACT
Pressure dependence of the Ce valence in CeCu(2)Ge(2) has been measured up to 24 GPa at 300 K and to 17 GPa at 18-20 K using x-ray absorption spectroscopy in the partial fluorescence yield. A smooth increase of the Ce valence with pressure is observed across the two superconducting (SC) regions without any noticeable irregularity. The chemical pressure dependence of the Ce valence was also measured in Ce(Cu(1-x)Ni(x))(2)Si(2) at 20 K. A very weak, monotonic increase of the valence with x was observed, without any significant change in the two SC regions. Within experimental uncertainties, our results show no evidence for the valence transition with an abrupt change in the valence state near the SC II region, challenging the valence-fluctuation mediated superconductivity model in these compounds at high pressure and low temperature.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Año:
2014
Tipo del documento:
Article
País de afiliación:
Japón