Mössbauer study of 57 Fe in CVD diamond following 57 Mn implantation

57 Fe Mössbauer spectroscopy, following the implantation of radioactive parent 57 Mn + ions, has been performed on two chemical vapour deposited diamond samples, one synthesized in 2003 (CVD03) and the other in 2005 (CVD05). The spectra of sample CVD05 were as observed previously in natural IIa diamonds: single lines corresponding to substitutional and interstitial Fe were superimposed on a broad quadrupole split doublet. The site fraction of Fe i reached 30% at 900 K. The spectra of the CVD03 sample showed, in addition to the above features, a strong contribution (>30%) from a quadrupole doublet attributable to the presence of intrinsic amorphous inclusions in the crystallites. This observation has been confirmed by X-ray diffraction.