Zinc-67 Mössbauer Spectroscopy

Abstract

Since the early days of the Mossbauer effect, the main attraction of the 93.31-keV transition in 67Zn has been the extremely high resolution for the determination of small changes in the γ-ray energy.1–9 This exceptionally high sensitivity has been used for precision measurements of hyperfine interactions and in gravitational redshift experiments. In recent years, several new developments have occurred. From the point of view of the instrumentation, a new type of spectrometer has been built that allows the application of external pressures up to ~10 GPa in the temperature range from 1.5 to 100 K. In addition, it has been demonstrated that the 67Zn Mossbauer resonance is also a highly favorable tool for studying lattice dynamic effects.10–12 As a consequence, this resonance has been applied to investigate the volume and temperature dependence of hyperfine interactions and lattice dynamics in a variety of new systems including Zn metal and Zn alloys, semiconducting and insulating compounds, in particular Zn chalcogenides as well as normal and inverse spinels. Fortunately, this experimental activity also stimulated theorists’ interest and theoretical calculations have become available in recent years on ZnF2, Zn chalcogenides, Zn metal, and alloys. We will describe most of these new developments. Since emphasis will be put on intrinsic properties of materials, we will not mention experiments on phase modulation of recoilless γ radiation,13,14 and more recent measurements of the gravitational redshift.8 The early history of 67Zn Mossbauer spectroscopy and a large part of the results published up to 1982 have been covered by two previous review articles.15,16