Fluorine-Kα and Chlorine-Kβ Emission Spectra from Alkali Fluorides and Chlorides

抄録

The fluorine-Kα and chlorine-Kβ emission spectra in fluorescence from a series of alkali halides MX (M=Li, Na, K, Rb and Cs; X=F and Cl) are measured with a high-resolution two-crystal spectrometer. Solid-state effects are observed on the intensities of the K¹L¹ and Kβ_x satellite peaks in the Kα and Kβ emission spectra, respectively. An anomalously low intensity of the K¹L¹ satellite peak is observed for KF. The measured emission spectra are presented along with the UPS spectra of the F⁻ 2p and Cl⁻ 3p valence bands obtained by Poole et al., the fluorine K absorption-edge spectra by Nakai et al. and the chlorine K absorption-edge spectra by the author. By using these spectra, the first shoulder at the K absorption edge is identified as being due to a core exciton, the energy level of which is formed below the bottom of the conduction band. The binding energy of the exciton is estimated.