Spin and Valence-Fluctuation Mediated Superconductivity in Pressurized Fe and CeCu2(Si/Ge)2

D. Jaccard; Alexander T. Holmes

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arXiv · cond-mat/0410143

Spin and Valence-Fluctuation Mediated Superconductivity in Pressurized Fe and CeCu2(Si/Ge)2

D. Jaccard·Alexander T. Holmes

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Abstract

We review the evidence supporting valence-fluctuation mediated superconductivity in CeCu2Si2 and CeCu2Ge2, where Tc reaches 2.4 K at high pressure. In these systems the valence and magnetic critical points, at p_V and p_c respectively, are well separated. Characteristic signatures associated with both phenomena are distinct. In contrast, the valence and spin fluctuation regions appear much closer in most Ce based compounds. Concerning d-transition metals, superconductivity in pure iron emerges in the pressure window 15-30 GPa with the onset of Tc up to almost 3 K. All relevant observations point to unconventional superconductivity, likely mediated by ferromagnetic spin fluctuations.

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D. Jaccard, Alexander T. Holmes. 2004-10-06. Spin and Valence-Fluctuation Mediated Superconductivity in Pressurized Fe and CeCu2(Si/Ge)2. https://arxiv.org/abs/cond-mat/0410143

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