X-RayK-Absorption Spectra of Solid Argon and Krypton

Abstract

The x-ray $K$-absorption edge structures of argon (at 3.86 A) and of krypton (at 0.86 A) have been measured in the gaseous and solid states. The spectra of the gases confirm previous work. The spectra of the solids exhibit pronounced structure extending far to the short-wavelength side of the absorption edge. The broad absorption maxima observed can be correlated with the valence bands in the crystal, but the extremely sharp initial rise requires an unusual density of states in the bands, perhaps offering evidence for the existence of excitation states.