Coordination Quenching of the Saturation Magnetization of Potassium Ferricyanide

An experimental investigation of the result of competition of interatomic interaction forces with the Russell-Saunders coupling has been carried out by magnetization measurements on potassium ferricyanide up to near saturation. Since the asymptotic value of the saturation moment is found to be one Bohr magneton per atom of iron, the application of the Pauli principle seems to give support to the Van Vleck theory of removal of orbital degeneracy of the ${}_{}{}^6{}_{}{}^{}S$ state of ${\mathrm{Fe}}^{+++}$. The results are obtained through a sample motion technique, the sample being kept at temperatures between 1.3 and 4.2°K and studied in magnetic fields up to 60 000 gauss.