Paramagnetic Resonance Absorption in Two Sulfates of Copper

Resonance absorption measurements in CuS${\mathrm{O}}_4$ · 5${\mathrm{H}}_2$O and Cu${\mathrm{K}}_2$ ${\left(\mathrm{S}{\mathrm{O}}_4\right)}_2$ · 6${\mathrm{H}}_2$O exhibit dissimilarities caused by different degrees of exchange coupling between paramagnetic ions. In the single salt, in which the ions are more closely spaced, exchange coupling causes the absorption lines to be much narrower than would be predicted on the basis of ordinary magnetic dipolar broadening, and causes the appearance of a single line in cases where two lines should otherwise be found. Neither of these effects is observed in the double salt.