Sensitivity of Fe-57 emission Mossbauer spectroscopy to Ar and C induced defects in ZnO

Emission Mossbauer Spectroscopy (eMS) measurements, following low fluence (<10(12) cm(-2)) implantation of Mn-57 (t(1/2) = 1.5 min.) into ZnO single crystals pre-implanted with Ar and C ions, has been utilized to test the sensitivity of the Fe-57 eMS technique to the different types of defects generated by the different ion species. The dominant feature of the Mossbauer spectrum of the Ar implanted ZnO sample was a magnetic hyperfine field distribution component, attributed to paramagnetic Fe3+, while that of the C implanted sample was a doublet attributed to substitutional Fe2+ forming a complex with the C dopant ions in the 2(-) state at O vacancies. Magnetization measurements on the two samples, on the other hand, yield practically identical m(H) curves. The distinctly different eMS spectra of the two samples display the sensitivity of the probe nucleus to the defects produced by the different ion species.