Magnetic properties of two complex ferric paramagnetics

The magnetic susceptibility of two complex ferric compounds in both the solid state and solution — ferric ammonium citrate and potassium (hexa)cyanoferrate (III) — was measured. On the basis of measurements of other physical constants the magnetic moments were calculated from the susceptibility and with citrate also from the longitudinal relaxation time of nuclear magnetic resonance. Some magnetic measurements of these substances made hitherto were verified and missing data were found. The results show that for citrate the magnetic moment from both the solid state and solution is smaller than purely spin moment, which confirms the opinion that it is a mixture of several components having different values of the Weiss constant. With potassium ferricyanide the opposite is the case, which indicates that the orbital moment, the contribution of which in the solid state is relatively larger than in solutions, is not quite suppressed. In both materials an excess of carriers of relatively larger magnetic moments appears in dilute solutions than in concentrated ones. The results obtained for a solution of potassium ferricyanide differed from the earlier measurements of Collet.