Emission Mössbauer spectroscopy on 57Fe fed by 57Mn ions implanted in the metal oxides ZnO, MgO and Al2O3 has been performed. The implanted ions occupy different lattice sites and charge states. A magnetic part of the spectra in each oxide can be assigned to Fe3 + ions in a paramagnetic state with unusually long relaxation time observable to temperatures up to several hundreds Kelvin. Earlier expectations that the magnetic spectra could correspond to an ordered magnetic state could not be confirmed. A clear decision for paramagnetism and against an ordered magnetic state was achieved by applying a strong magnetic field of 0.6 Tesla. The relaxation times deduced were compared to spin–lattice relaxation times from electron paramagnetic resonance (EPR).
1 Apr 2010
Volume: 197 Issue: 1-3 Pages: 43-52