PRODUCTION OF VACANCIES AND OTHER DEFECTS IN KBR AT LOW TEMPERATURES

The production rate of vacancies and interstitial defects formed by ionizing radiation in KBr has been studied at low temperatures. It has been found that the large difference between the production rate of vacancies at liquid helium temperature (LHeT) and liquid nitrogen temperature (LNT) may be accounted for by a combination of thermal annealing processes, interstitial stabilizing processes, and certain additional processes requiring the action of the radiation at LNT. The increase in the production efficiency of vacancies between LHeT and LNT, as predicted by the excitonic mechanism of defect production, is not observed. Studies of the bands produced on warming a crystal irradiated at LHeT to LNT indicate that the V4‐band is the major band produced and that it is produced from the H‐band. The V4‐envelope formed during irradiations at LNT is shown to consist of the V4‐band produced as above, with the addition of bands at 266 and 306 nm. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim