Absorption Bands of RbCl-KCl Mixed Crystals in the Extreme Ultraviolet Region

Abstract

Absorption bands of RbCl-KCl mixed crystals are studied in XUV region at room temperature, with particular attention to the behavior of the sharp multiplet bands characteristic of the cations. Position of the multiplets hardly depends upon the composition of the mixture and therefore the previous assignment of the multiplets to the exciton absorptions related with the quasi-intraionic transitions is confirmed. From the separation between the components of the multiplet of RbCl, the energy difference between the band bottoms at \(\varGamma\) and X points in the conduction band and also the spin-orbit separation of the uppermost cation core band are determined.