Search

57Fe Mössbauer spectroscopy, following the implantation of radioactive parent 57Mn + 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 Fei 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. [ABSTRACT FROM AUTHOR]

We report on the detection of Fe i –B pairs in heavily B doped silicon using 57Fe emission Mössbauer spectroscopy following implantation of radioactive 57Mn+ parent ions ( T 1/2 = 1.5 min) at elevated temperatures > 850 K. The Fe i –B pairs are formed upon the dissociation of Fe i –V pairs during the lifetime of the Mössbauer state ( T 1/2 = 100 ns). The resulting free interstitial Fei diffuses over sufficiently large distances during the lifetime of the Mössbauer state to encounter a substitutional B impurity atom, forming Fe i –B pairs, which are stable up to ∼1,050 K on that time scale. [ABSTRACT FROM AUTHOR]

The hyperfine interactions of six different PAC (perturbed angular correlations) probes in the ferromagnetic spinel semiconductor HgCr2Se4 have been investigated. Thereby the site occupation of the probes was determined and opposed to that in other comparable substances. All of the three lattice sites could be tested. Theoretically calculated hyperfine fields (WIEN97) were compared with the experimental values. [ABSTRACT FROM AUTHOR]

Radioactive 57Mn isotopes have been implanted into Si1 − x Ge x crystals ( x ≤ 0.1) at elevated temperatures for Mössbauer studies of the diffusion of interstitial 57Fe daughter atoms. The atomic jump frequency is found to increase upon Ge alloying. This is attributed to a lowering of the activation energy, i.e. the saddle point energy at hexagonal interstitial sites with Ge neighbour atoms. [ABSTRACT FROM AUTHOR]