Mixed-valence intermediates isomers

As mentioned in the Introduction (section 1), the electrical resistivity, specific heat, magnetic susceptibility and thermoelectric power anomalies of concentrated lanthanide Kondo systems are qualitatively similar to those found in the dilute lanthanide systems discussed previously. However the importance of the concentrated systems is that they provide a totally new view of Kondo-like phenomena. Lattice constant. X-ray photoemission (XPS) and Mossbauer isomer shift measurements indicate a strong correlation between systems that exhibit Kondo-like anomalies and systems in which the lanthanide ion has a mixed or intermediate valence. By mixed valence we mean that there are two 4f electron configurations accessible to each rare earth ion (e.g., Ce -Ce, Eu -Eu ", Yb -Yb ). Phenomenologically the traditional... 

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