IBMS

Mössbauer spectroscopy is an outstanding non-destructive method for the qualitative and quantitative analysis of solid samples containing suitable Mössbauer active elements in high enough concentrations. Our ⁵⁷Fe, ¹¹⁹Sn and ¹⁹⁷Au Mössbauer spectrometers enable the characterization of iron-, tin- and gold-containing solid materials, respectively. Materials with natural isotopic composition of Fe, Sn and Au can be readily measured in all the three cases. Mössbauer spectra reflect on the magnetic and chemical state of the Mössbauer active element. Respective Mössbauer spectra can often clearly indicate the presence and relative occurrence of iron, tin and gold atoms with different oxidation states in the sample. Different phases, atomic- and ligand environments of iron, tin and gold atoms may be detected and distinguished. Identification of known phases of Fe/Sn/Au may be possible.

Samples should be either powders or thin layers. ⁵⁷Fe and ¹¹⁹Sn Mössbauer measurements are performed at ambient temperature (ca. 293-300 K), while ¹⁹⁷Au Mössbauer measurements are carried out with the absorber and the source both being cooled to the same temperature typically lying in the range of 4.2-25 K. The latter temperatures are achieved by applying liquid helium cooling in a suitable CryoVac cryostat system. Individual Mössbauer measurements typically take 1-5 days to complete.

Mössbauer spectroscopy is an outstanding non-destructive method for the qualitative and quantitative analysis of solid samples containing suitable Mössbauer active elements in high enough concentrations. Our ⁵⁷Fe, ¹¹⁹Sn and ¹⁹⁷Au Mössbauer spectrometers enable the characterization of iron-, tin- and gold-containing solid materials, respectively. Materials with natural isotopic composition of Fe (natural abundance of ⁵⁷Fe is ca. 2.12%), Sn (natural abundance of ¹¹⁹Sn is ca. 8.59%) and Au (¹⁹⁷Au: 100%) can be readily measured in all the three cases. Mössbauer spectra reflect on the magnetic and chemical state of the Mössbauer active element. Respective Mössbauer spectra can often clearly indicate the presence and relative occurrence of iron, tin and gold atoms with different oxidation states in the sample. Different phases, atomic- and ligand environments of iron, tin and gold atoms may be detected and distinguished. Identification of known phases of Fe/Sn/Au may be possible. Individual Mössbauer measurements typically take 1-5 days to complete.

Samples should be either powders or thin layers. The sample holder can hold up to ca. 1 g of powdered sample. This should contain at least 5 mg of Fe/Sn or at least 30 mg of Au to facilitate the measurement of ⁵⁷Fe/¹¹⁹Sn/¹⁹⁷Au Mössbauer spectra with acceptable S/N ratio. Two Mössbauer spectrometers are available: one for measurements at ambient temperature (ca. 293-300 K, applied for ⁵⁷Fe and ¹¹⁹Sn Mössbauer measurements) and one for ¹⁹⁷Au Mössbauer measurements that are carried out with the absorber and the source both being cooled to the same temperature typically lying in the range of 4.2-25 K. The latter temperatures are achieved by applying liquid helium cooling in a suitable CryoVac Konti-IT-Spektro-He cryostat system. Both spectrometers are based on a high accuracy Wissel Mössbauer spectrometer system utilizing Wissel’s MVT-1000 Mössbauer Velocity Transducer, MR-360 Mössbauer Drive Unit, DFG-1000 Digital Function Generator and CMCA-550 Data Acquisition Module, among others. To optimize S/N ratio of the measured spectra, a Saint-Gobain scintillation detector is applied when measuring ¹⁹⁷Au and ¹¹⁹Sn Mössbauer spectra, while an LND-45431 (Kr) proportional counter is used for the purposes of ⁵⁷Fe Mössbauer spectroscopy. For ⁵⁷Fe and ¹¹⁹Sn Mössbauer measurements commercial radioactive sources of ⁵⁷Co(Rh) and ^119mSn(CaSnO₃) are applied, respectively. ¹⁹⁷Au Mössbauer spectroscopy is performed by using a ¹⁹⁷Pt radioactive source prepared via neutron irradiation of a Pt foil (94.57% enriched in ¹⁹⁶Pt) in the Budapest Research Reactor. The ¹⁹⁶Pt(n,γ)¹⁹⁷Pt reaction produces the Mössbauer source with a half-life of ca. 19.9 hours, which remains then usable for a few days.