Publisher Summary Mossbauer spectroscopy can be likened to ultraviolet spectroscopy. Both techniques employ a source of radiation, an absorber and a detector. In Mossbauer spectroscopy, we consider transitions between nuclear energy levels with the emission and absorption of y rays; whereas, in ultraviolet spectroscopy, we consider the transitions between electronic energy levels with the emission and absorption of ultraviolet radiation. To observe resonance, a range of source photon energies is scanned: in ultraviolet by the use of a prism or grating, and in Mossbauer by employing the Doppler effect. The energy of the y ray (E,) is varied by the well-known Doppler formula d E = (V/C)E, where AE = change in energy of y photon, 11 = velocity of source relative to the absorber, and c = velocity of light. As in ultraviolet, absorption is plotted versus the energy of source photon (usually in velocity units for Mossbauer). Different compounds of one isotope give different spectra— that is, the nuclear energy levels are sensitive to the extranuclear environment. These differences in spectra can be attributed to the hyperfine interactions; the interactions between the nuclear charge distribution, and the extranuclear electric and magnetic fields. These hyperfine interactions give rise to the isomer shift (IS.) , the quadrupole splitting (Q.S.), and the magnetic Zeeman splitting.

Mössbauer Spectra of Inorganic Compounds: Bonding and Structure

Mössbauer isomer shifts of crystalline antimony compounds

The role of Sb5+ in the structure of Sb2O3–B2O3 binary glasses—an NMR and Mössbauer spectroscopy study

Identification of the intercalant species in SbCl5-graphite using Mössbauer spectroscopy

Probes of structural and electronic environments of phosphor activators: Mössbauer and Raman spectroscopy.

Mossbauer spectra of 121Sb in all the binary antimony halides have been obtained, as well as in cubic Sb2O3. The isomer shifts relative to the 121SnO2 source are − 11.3 mm/sec (Sb2O3), − 13.8 (SbCl3), − 13.9 (SbBr3), − 15.9 (SbI3), − 14.6 (SbF3), + 2.2 (SbF5), and − 3.12 (SbCl5). Quadrupole splittings were obtained for most of the antimony(III) compounds. The linear variation of isomer shift with ligand–metal electronegativity difference for Sb2O3, SbCl3, SbBr3 and SbI3 is interpreted as due to a constant s character in the ligand–metal bonds. The SbF3 does not obey this relationship due to its radically different geometry.

L. H. Bowen

Papers

121Sb Isomer Shifts in Antimony Halides