Dipolar Defects in Rare-Earth Doped Alkaline-Earth Fluorides

摘要

It has become clear that simple point-defect models of relaxations in doped alkaline-earth fluorides are insufficient to explain experimental results. The idea that clusters of rare-earths may be associated with observed relaxations has been suggested. The writer attempted to study calcium fluoride crystals doped with two different rare-earth species, utilizing dielectric relaxation and ionic thermocurrent techniques to investigate the cluster hypothesis. If, in fact, a relaxation is associated with a dipolar cluster, hybrid relaxation involving both rare-earth species present should be observed. The finding (enclosed) provides useful new information concerning the defect structure of rare-earth doped calcium fluoride. (Author)