On the interpretation of Mossbauer isomer shifts

Abstract

Isomer shifts pertaining to a large variety of isotopes (⁵⁷Fe, ⁹⁹Ru, ¹⁵¹Eu, ¹⁵⁵Gd, ¹⁹³Ir, ¹⁹⁵Pt and ¹⁹⁷Au) measured in numerous intermetallic compounds and solid solutions have been interpreted in the past in terms of the model of Miedema and van de Woude (1980). In this model the isomer shifts of a given isotope in a series of intermetallic compounds can be described by means of the same pair of constants P' and Q', reflecting the effect of interatomic charge transfer and intra-atomic s-d electron conversion, respectively. The values of P' and Q' can differ markedly from one isotope to another. It is shown that a uniform pair of values of P' and Q' applies for all isotopes after scaling the original P' and Q' values to the specific nuclear and electronic properties of the various isotopes.