Emission Mössbauer spectroscopy study of fluence dependence of paramagnetic relaxation in Mn/Fe implanted ZnO.

Emission Mössbauer Spectroscopy following the implantation of radioactive precursor isotope Mn ( T= 1.5 min) into ZnO single crystals at ISOLDE/CERN shows that a large fraction of Fe atoms produced in the Mn beta decay is created as paramagnetic Fe with relatively long spin-lattice relaxation times. Here we report on ZnO pre-implanted with Fe to fluences of 2×10, 5×10 and 8 × 10 ions/cm in order to investigate the dependence of the paramagnetic relaxation rate of Fe on fluence. The spectra are dominated by magnetic features displaying paramagnetic relaxation effects. The extracted spin-lattice relaxation rates show a slight increase with increasing ion fluence at corresponding temperatures and the area fraction of Fe at room temperature reaches a maximum contribution of 80(3)% in the studied fluence range. [ABSTRACT FROM AUTHOR]