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RESEARCH PRODUCT
Comparative Mössbauer spectroscopic study of iron impurities in ZnSe
U. W. PohlLászló BottyánT. Becze-deákBéla MolnárP. BonvilleD. L. NagyHartmut Spieringsubject
Valence (chemistry)Mössbauer effectAbsorption spectroscopyChemistryInorganic chemistryAnalytical chemistryGeneral ChemistryActivation energyCondensed Matter PhysicsNucleogenicImpurityMössbauer spectroscopyGeneral Materials ScienceSingle crystaldescription
Abstract An anomalous spectral doublet attributed to Fe 2+ impurity pairs is observed in Mossbauer absorption spectra of 57 Fe 0.01 Zn 0.99 Se below room temperature. In Mossbauer emission experiments, ZnSe: 57 Co polycrystal and powder sources exhibit below 45 K the nucleogenic Fe 1+ valence state born as an after effect of the electron-capture decay of 57 Co. Above 8 K, the proportion of the nucleogenic Fe 1+ decreases under the effect of the thermally activated Fe 1+ →Fe 2+ relaxation. The activation energy is estimated to 0.004 eV. While nucleogenic Fe 1+ is absent in ZnSe: 57 Co single crystal spectra, increasing proportions are detected in samples with an enhanced specific surface. The formation model of the nucleogenic Fe 1+ is extended to other zinc chalcogenides and a tentative model is developed, which shows the role of the surface electric field in limiting the formation of nucleogenic Fe 1+ in well crystallised source samples.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2001-04-01 | Journal of Physics and Chemistry of Solids |