Width of AtomicL2andL3Vacancy States nearZ=30

Abstract

Consequences of the discontinuity at $Z=30\mathrm{}$ in the Coster—Kronig transition probability $f_{23}$ have been investigated by Auger and photoelectron spectroscopy. The $\frac{L_3-M_{45}{M}_{45}}{L_2-M_{45}{M}_{45}}$ Auger intensity ratio is found to undergo a sudden decrease at $Z=30\mathrm{}$. Relative $L_2$ and $L_3$ level widths of Cu and Zn are derived from photoelectron spectra; while the $L_3$ width increases from Cu to Zn, the $L_2$ width of Cu is greater than that of Zn, contrary to the general trend. The data agree qualitatively with earlier calculations of radiationless-transition probabilities based on hydrogenic wave functions, but substantial quantitative discrepancies are found. New calculations have been performed with numerical single-particle wave functions based on Green's atomic independent-particle model. With suitable assumptions regarding Cu and Zn $M_4$ and $M_5$ electron binding energies in the presence of an $L_2$ vacancy, reasonable agreement between calculated and observed Auger-electron intensity ratios and $L$-subshell level widths is attained.