Application of the Mössbauer effect in 129I as a spectroscopic tool for chemical structures and lattice dynamics investigation

Abstract

This paper deals with the interpretation of the Mössbauer effect (ME) of the 28 keV level in I¹²⁹ and the analysis of the deduced constants in terms of chemical structure and lattice dynamics. The calculation of the magnitude and sign of e²qQ, the η parameter and the isomer shift from the quadrupole splitting spectrum is described. These parameters are directly related to the p electron population in iodine. The effect of the behaviour of the anisotropic recoilless fraction ƒ on the various Δm transition intensities is demonstrated. Illustrations of the application of the ME in I¹²⁹ for the structural determination of some tellurium compounds are given. CrI₃ is cited as an example of a magnetic iodine compound and its spectra above and below the Curie temperature are analyzed. Finally, possible trends for future studies of the ME in I¹²⁹ are outlined.