Behavior of interstitial halogen in the production process

The extent of the interaction between interstitial halogen and Na+ and H center in the production process was determined in the temperature range in which H center became thermally unstable. The optical absorption change in Na+-doped KBr crystals in course of time was obtained by pulsed electron beam irradiation. Hsub(A) band was seen. The production rate of Hsub(A) center increased with rising irradiation temperature in comparison with the rate of H center. This means the increasing probability of the interaction between interstitial halogen and Na+. The optical absorption in pure KBr crystals was also measured, and the growth of V4 band as well as F and H bands was seen. Temperature dependence of the volume of interaction between interstitial halogen and Na+ ions and H center is shown in a figure. Two volumes are proportional to each other, and on Arrhenius plot with activation energy of (0.025 +- 0.005) eV. Discussion concerning this experiment is described. (Kato, T.)