Mössbauer effect in the presence of electronic relaxation: Application to theYb170nucleus

In this study of the Mössbauer line shape in the presence of electronic relaxation, we first compare the stochastic model of Clauser and Blume with the perturbation theory of Hirst and discuss the physical concepts underlying these two theories. We then derive the algebraic expression for the Mössbauer line shape in the presence of relaxation for a nuclear transition ($2^{+}$ → $0^{+}$) in the case of an electronic spin $S=\frac{1}{2}$ and of axial hyperfine interactions; the resulting formulas were applied to a case of isotropic hyperfine interactions, i.e., to the relaxation spectra of ${}_{}{}^{170}{}_{}{}^{}\mathrm{Yb}$ in gold.