Degree of valence mixing

A first analysis of the susceptibility has been given on the basis that the susceptibility is the sum of the various Sm " and Sm " " susceptibilities, given by their relative concentration according to the degree of valence mixing, i.e., the compound is assumed... 

In spite of the fact that the fits in figs. 25 and 26 are very good, it leaves one rather unsatisfied because the degree of valence mixing for SmBs (0.3 and 0.7) is not what the more recent numbers yield (0.4 and 0.6). However, the model used for the computation of the susceptibility corresponds in a simple way to the alloy analog of the Anderson lattice model, which has been shown to give good results, e.g. by... 

Electronic properties of TmSe. In the early days of research on intermediate-valent TmSe a lot of diserepaneies occurred between the main research centers of that time, AT T and IBM, about the physical properties and degree of valence mixing of TmSe (see, e.g.. Parks 1976). The reason was that TmSe exists with various stoichiometries and the stoichiometry had not been controlled in the 1970 s. However, there was never a question that TmSe can be prepared in an intermediate-valent form and in fig. 61 we show a XPS spectrum of TmSe where the divalent and trivalent final state spectra can be discerned with their typical ladder-like structure. 

This example with Eu and Pd demonstrates first of all how the valence state of a lanthanide can be determined by the presence of the well separated Ln and Ln emission features. For the mixed-valent compound it is furthermore possible to establish the degree of valence mixture from the relative intensities of the two emission features. The relative stabilities of the divalent and trivalent configurations are also revealed by the position of the divalent photoemission features in the different compounds. Therefore one can determine for each compound by how much the divalent configuration is stabilized by the surface. 

Upon reduction, WO3 forms mixed-valence (WjWj W ) tungsten bronzes, H WOj, which have different colors depending on the degree of reduction, x [see Eq. (33.1)]. Due to parasitic reaction, such as hydrogen evolution, and decreased... 

Lanthanides with fractional valences have II, III and IV valences, as well as mixed II/III and III/IV valences. Depending on temperature and pressure, the degree of oxidation can change. This effect may result in a change in the different properties of nanoparticles, such as the stability, heat capacity, conductivity and magnetic susceptibility [218]. Valence fluctuation phenomena have been reported to occur... 

This classification distinguishes two degrees of mixing of two different configurations of a mixed-valence dimer Ma - and - Mb", where A and B... 

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