Experimental interatomic Auger rates in sodium halides

Interatomic Auger transition rates of holes in the two outermost alkali-metal ion core levels have been measured in the sodium halides. The Na 2s core hole, which decays via a singly interatomic Coster-Kronig process, has a lifetime width of 0.75±0.15, 0.45±0.10, and 0.46±0.10 eV in NaF, NaCl, and NaBr, respectively. The 2p hole, which decays via a doubly interatomic process, has a lifetime width of 0.10±0.05 and <0.06 eV in NaF and NaCl, respectively. The large phonon broadenings determined here, ranging from 0.7 to 1.0 eV in the different sodium halides, are in excellent agreement with calculated values and are responsible for the large uncertainty limits on the determined lifetimes. The absolute values of the Na 2s and 2p lifetime widths are comparable to those from theoretical calculations.