Abstract

Defect equilibria in fluorite materials have been extensively studied. The behavior does not agree with that expected from simple mass action relationships. Competing equilibria caused by extensive defect clustering are found to be very important such as scavenging of interstitial fluoride $\left({\text{F}}_{\text{i}}^{{}^{\prime }}\right)$ by the clusters to make negatively charged clusters (1). CdF₂ is the only one of the fluorites that can be converted to a semiconductor by heating. It is also a system where scavenging equilibria might be particularly important because the higher electron affinity of Cd²⁺ would result in stabilization of the scavenged clusters by delocalization of the excess negative charge.

© 1984 Optical Society of America