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Electron Binding in Metals: Grey and White Tin

1973; American Physical Society; Volume: 8; Issue: 8 Linguagem: Inglês

10.1103/physrevb.8.3569

0556-2805

Robert M. Friedman, R. E. Watson, J. Hudis, M. L. Perlman,

Advanced Chemical Physics Studies

Core-electron binding-energy-shift data, obtained from photoelectron spectroscopy, are presented for $\ensuremath{\beta}\ensuremath{-}\mathrm{Sn}$ and $\ensuremath{\alpha}\ensuremath{-}\mathrm{Sn}$. These data and published results for the M\"ossbauer isomer shift and for internal conversion of $^{119}\mathrm{Sn}$ in the $\ensuremath{\beta}$ form have been analyzed in terms of free-atom valence-electron wave functions renormalized to the Wigner-Seitz radii characteristic of the two solids. The three sets of experimental data are readily accounted for in this analysis: $\ensuremath{\beta}\ensuremath{-}\mathrm{Sn}$ turns out to have 1.6 \ifmmode\pm\else\textpm\fi{} 0.3 $5s$ electrons; and the transition $\ensuremath{\beta}\ensuremath{-}\mathrm{Sn}\ensuremath{\rightarrow}\ensuremath{\alpha}\ensuremath{-}\mathrm{Sn}$ is associated with a surprisingly small change, 0.1e to 0.2e, of valence-$s$ to valence-$p$ character. The concepts embodied in this analysis must be applied to the analysis of electron-binding-energy shifts observed in alloys and compounds, both insulating and metallic.