Temperature dependence magnetic parameters

The effect of intraligand substitution on the spin crossover behaviour in these systems has been further investigated using various techniques188). Variable temperature Mossbauer spectra show the quadrupole doublets of the two coexisting spin states. Thermodynamic parameters have been derived from the temperature dependent magnetic susceptibility data. AH has been found to be 4.8,3.1, and 4.8 kcal mol-1 for II, III, and IV, serially, in the solid state, and 4.6 and 2.8 kcal mol-1 for II and III, respectively, in solution. 

For example, 0 describes the temperature dependence of composition near the upper critical solution temperature for binary (liquid + liquid) equilibrium, of the susceptibility in some magnetic phase transitions, and of the order parameter in (order + disorder) phase transitions. 

The esr data of Prins and Reinders 144) were also used by Sohn, Hendrickson, and Gray 146) in a preliminary interpretation of their magnetic susceptibility measurements 99). Thus the g values reported were found to lead to the prediction of a substantial temperature dependence of the moment over the range studied, which was not in fact observed however, the data could be accommodated by assuming either that the distortion parameter, A, increased from about 300 to around 700 cm-1 between 4.2 K and 300 K, or that the 22+(ct 54) state lay only some 350 cm-1 above the ground level. 

Ishikawa etal. proposed an approach for the determination of the ligand-field (LF) parameters of a set of isostructural lanthanide complexes. This method consists of a simultaneous fit of the temperature dependence of magnetic susceptibilities and NMR spectra for the whole isostructural series [18]. In order to avoid over-parametrization a key restriction is imposed each parameter is expressed as a linear function of the number of f electrons, n ... 

Fig. 26. Temperature dependence of the hyperfine magnetic field and of the longitudinal relaxation parameter in NpSns. The J = 1/2 Brillouin curve for the temperature dependence of is shown. (Gal et al, )...

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