Kondo anomalies thermoelectric power

The interaction between impurity ions with partially filled d or f electron shells and the conduction electrons of a metallic host can lead to variations in certain physical properties with temperature and magnetic field which have come to be associated with the Kondo effect . In zero magnetic field, these temperature-dependent anomalies in the physical properties scale with a characteristic temperature Tk, the so-called Kondo temperature, above which the matrix-impurity system behaves magnetically and below which the matrix-impurity system behaves nonmagnetically. The physical properties which exhibit anomalies attributable to the Kondo effect include the electrical resistivity, magnetic susceptibility, thermoelectric power, specific heat and, in systems where appropriate, superconducting properties such as the critical temperature and the jump in specific heat which occurs at T. ... 

The reader is cautioned to observe, however, that existing theories for the various physical properties of Kondo systems do not provide a self-consistent definition for the characteristic temperature as defined by the temperatures of the typically broad anomalies in the thermoelectric power, electrical resistivity, heat capacity and magnetic susceptibility. Thus the values of the characteristic temperature inferred from different measurements may differ by as much as an order of magnitude. 

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... 

However if there is an electronic scattering mechanism present which leads in t(small term aalEp in order to obtain a nonvanishing thermoelectric power. For example the giant thermopowers of Kondo systems are due to that effect. As will be demonstrated below there are also anomalies in the thermopower due to CEF-splitting. 

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