Samarium compounds susceptibility

For SmCj, as mentioned above, the reciprocal susceptibility does not obey the Curie-Weiss law above the Neel temperature of 21 K (Sakai et al. 1981a) in contrast to the results of Vickery et al. (1959). This anomalous magnetic behavior resembles that reported for other samarium compounds and seems to be attributed to the contribution of the first excited multiplet state (J = j) to the value. 

A study of the crystal field interaction in NdAlg by heat capacity, susceptibility, and resistivity measurements over the range 4—300K has been reported. Thermal transformations in thiourea compounds of neodymium, samarium, europium, and gadolinium have been shown to take place according to the scheme M(C3H302)3, CS(NH2)2,3H20 M(C3M,02) CSfNH ) NH CNS MO-... 

Grignard type compounds of some lanthanide metals in the oxidation state +2 have been investigated by D.F. Evans et al. (1970, 1971). Europium, samarium and ytterbium react in tetrahydrofuran with alkyl and aryl iodides between —20 and + 30°C forming colored solutions containing mixtures of compounds, which give some Grignard-type reactions. Characterization of the compounds was done only by magnetic susceptibility measurements and some titrimetric analyses. 

In the case of Eu and Yb the reactions proceed at temperatures ranging from -40 to -20 C. Samarium is less active and after an activation by treatment with iodine interacts with RI at 30 C to give blue-green solutions of RSml. The solutions of Eu and Yb derivatives are brown. The products were not isolated from the reaction mixture as individual compounds, however the formation of them is reliably confirmed by the data of acidimetry and iodometry, reactions with iodine, as well as by reactions characteristic for Grignard reagents with Michler s ketone, water, benzophenone, Me3SiCl. The measurement of magnetic susceptibility has shown that in the Eu and Yb complexes from 85 to 100% of the metal is in bivalent state. In the Sm complexes up to 50% of the metal is present as Sm(III). 

Thus magnetic susceptibility measurements provide an interesting means of evaluating percentages of Ln and Ln + ions in a mixture of species. Effective magnetic moments of divalent samarium and ytterbium compounds are listed in table 5. 

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