Low-temperature radiation damage in Mn-doped RbMgF3

Abstract

Defects introduced by high energy electron irradiation at low temperatures have been studied in manganese doped RbMgF3. At these low temperatures negative-ion vacancies are not mobile and only the various radiation induced interstitials and X2- (VK) centres are mobile. It is found that at 15K where X2- centres are not mobile the F band (due to negative vacancies which have trapped electrons) increases almost linearly with radiation dose and optical bands due to X2- centres and impurities yield the only obvious absorption between 200 nm and 1000 nm. No sign of radiation defect perturbed Mn2+ optical transitions can be observed for the radiation doses investigated. However, when the irradiation is done at 77K both F centres and radiation defect-Mn2+ complexes are formed. Since vacancies are not mobile at 77K it is suspected that interstitial defects perturb the Mn2+ ions.