Crystallographically-based analysis of the NMR spectra of maghemite

All possible iron environments with respect to nearest neighbour vacancies in vacancy-ordered and vacancy-disordered maghemite have been evaluated and used as the foundation for a crystallographically-based analysis of the published NMR spectra of maghemite. The spectral components have been assigned to particular configurations and excellent agreement obtained in comparing predicted spectra with published spectra taken in applied magnetic fields. The broadness of the published NMR lines has been explained by calculations of the magnetic dipole fields at the various iron sites and consideration of the supertransferred hyperfine fields.

▸ Analysis of 57Fe NMR of maghemite based on vacancy ordering and nearest neighbour vacancies. ▸ Assignment of NMR spectral components based on crystallographic analysis of unique iron sites. ▸ Strong agreement between predicted spectra and published spectra taken in applied magnetic fields. ▸ Maghemite NMR spectral broadening due to various iron sites and supertransferred hyperfine field.