Photoelectron Spectra of PbCl₂, PbBr₂ and Similar Materials

Abstract

The photoelectron spectra of PbCl₂, PbBr₂ and SnCl₂, which have the lead chloride-type crystal structure, have been measured with X-rays and extreme ultraviolet rays in order to investigate the electronic structures of their valence bands. The photoelectron spectra of TlCl and Pbl₂ have also been measured for comparison because they have the same electronic configuration as PbCl₂ et al. though the crystal structures are different. It was found that the spectra of all above materials have a common feature, namely, the bands observed in the valence region consist of two parts, the lower binding energy band being much more intense than the other, and it further splits into three. It has been concluded that the higher part of the valence band of these crystals (the lower binding energy band) is mainly composed of p electrons of halogen ions but considerable admixing of metal s electrons is present.