Interconfigurational excitations

The pressiue dependence of the electrical resistivity of YbCuAl was investigated (Alami-Yadri et al. 1998, 1999a,b) up to 8 GPa. The resistivity at 300 K decreases with increasing pressure. At 8 GPa a dependence occurs at low temperature (Fermi-liquid behavior), and the Kondo temperature decreases with increasing pressure. The experimental setup for these measurements was presented by Jaccard et al. (1998). Furthermore, point-contact spectroscopy was used to measure the interconfigurational excitation energies and conduction-electron lifetime width of valence-fluctuating YbCuAl (Bussian et al. 1982). 

Fig. 1. Schematic energy level diagram of the in-terconfigurational fluctuation (ICF) model describing valence fluctuations between two 4f configurations (4r, 4r ), characterized by their /multiplet level structure. The basic parameters of the ICF model and denote the interconfigurational excitation energy and interconfigurational mixing width, respectively.

Fig. 8. Temperature dependence of (a) the interconfigurational excitation energy ( ,) and (b) the upper limit of the fluctuation temperature T, of EuPd Sij as directly revealed in the Raman spectra of fig. 5.

Barandiaran Z, Seijo L. Radial correlation effects on interconfigurational excitations at the end of the lanthanide series A restricted active space second order perturbation study of Yb and SrCl2 Yb +. J Chem Phys. 2013 138 074102. 

More importantly, in the context of orbital mapping or "electrochemical spectroscopy" the same redox-active orbital (dxy) figures in the primary CT process and in interconfigurational d-d excitations and in the d5/d6 reduction.. Do we find a faithful and illuminating correlation We have tested this on an archetypal system OSX4L2. This system starkly illustrates how the incremental electronic response to progressive substitution can be linear or non-linear depending on the nature of L (and X). 

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