The M -Series Absorption Spectrum of Metallic Bismuth
1934; American Institute of Physics; Volume: 46; Issue: 5 Linguagem: Inglês
10.1103/physrev.46.357
ISSN1536-6065
Autores Tópico(s)Thermodynamic and Structural Properties of Metals and Alloys
ResumoWith a vacuum spectrometer and sputtered bismuth films as absorbers, the five $M$-absorption edges were obtained. The large discrepancies between computed and observed wave-lengths of Bi ${M}_{\mathrm{IV}}$ and ${M}_{\mathrm{V}}$ were verified. The ${M}_{\mathrm{I}}$, ${M}_{\mathrm{II}}$ and ${M}_{\mathrm{III}}$ discrepancies were found to be of the order of experimental error. To explain the ${M}_{\mathrm{IV}}$ and ${M}_{\mathrm{V}}$ discrepancies it is assumed that electrons from ${M}_{\mathrm{IV}}$ and ${M}_{\mathrm{V}}$ levels, in an absorption act, go to virtual lattice levels above the filled conduction, or valence, levels of the crystal for the elements Ta73 to Th90. Data on, and Kronig's theory of, secondary x-ray absorption are shown to support this view. The application of the ordinary x-ray selection rule $\ensuremath{\Delta}l=\ifmmode\pm\else\textpm\fi{}1$, $\ensuremath{\Delta}j=\ifmmode\pm\else\textpm\fi{}1$ or 0 in $M$ absorption, suggested by Siegbahn, is further discussed. That there is a definite selection rule operating in $M$ absorption there is little room to doubt.
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