Chlorine-K-X-Ray Spectra and Electronic Band Structure of CuCl

The $K\beta$-emission and $K$-absorption spectra of chlorine in CuCl have been obtained with a 50-cm bent-quartz-crystal vacuum spectrograph. The spectra are discussed in terms of the energy-band structure. Results are evaluated by comparing the Cl $K$ spectra with the Cu $K$ and $L$ spectra, with the x-ray photoelectron spectrum, and with the theoretical band structure. It is confirmed that the upper valence band arises primarily from the $3d$ state of copper and the lower band predominantly from the $3p$ state of chlorine. The low-energy part of the conduction band arises from the $4s$ state of copper. The $p$-type states in the conduction band are located at several eV above the bottom.