The paramagnetic resonance spectra of two salts of manganese

Abstract

The magnetic resonance spectra of manganese fluosilicate and manganese ammonium sulphate have been analyzed using centimetre wave-lengths. It is shown that the splitting of the $^{6}$S state is due mainly to the non-cubic symmetry of the crystalline field; the effect of the cubic field, hitherto assumed to be dominant, appears only as a small correction. The spectra show that the splitting is consistent with a mechanism suggested by Abragam & Pryce (1951), where it is attributed to magnetic interaction between the five electrons constituting the $^{6}$S state. An extensive hyperfine structure is resolved, and the nuclear spin ($\frac{5}{2}$) of $^{55}$Mn is confirmed. The spectroscopic splitting factor, g, is 2$\cdot $000 $\pm $ 0$\cdot $001, very close to the free-spin value. The energy levels in zero magnetic field are evaluated for manganese ammonium sulphate.