Electron paramagnetic resonance of Mn2 in the ferroelectric phase of NaNO2

The electron paramagnetic resonance of Mn2+ ion doped in single crystals of sodium nitrite (NaNO2) has been studied at 9.5 kmc from room temperature (∼27°C) to 180°C. Only one magnetic complex of Mn2+ has been found. The complex gives different spectra in the ferro- and para-electric phases of the host crystal. The resonance lines of the allowed transitions at room temperature have been fitted to a spin-Hamiltonian of orthorhombic symmetry. The resonance lines show a strong angular dependence in their widths. The differences in line width and the presence of forbidden transitions along the principal axes are attributed to the spread in the crystal field due to the torsional oscillations of the NO-2 groups.