Absorption spectra of NaCl: Pb2+ at the A-band region

The origin of the absorption spectrum of NaCl:Pb²⁺ at the A-band region has been investigated. Main peaks are observed at 265, 273 and 290mμ in an untreated sample. In addition to the effect of lead concentration and thermal treatments, the luminescence and excitation spectra associated to the various bands have been determined. It is concluded that the 290 mμ band should be a composition of a number of bands corresponding to different types of simple dipole aggregates. The 265 mμ band, as well as the structure appearing in the region 220–260 mμ, is consistent with the existence of PbCl₂ precipitates.