Patterns of glow peak movement in rare earth doped lanthanum fluoride

Abstract

Low temperature thermoluminescence data from rare earth doped lanthanum fluoride is characterized by numerous glow peaks. These differ in temperature as a function of the substituted rare earth ion, dopant concentration and thermal annealing. Analysis of the component bands in terms of activation energy, frequency factor and kinetic order reveals simple patterns in which the movement of the glow peaks is related to the ionic radii of the rare earth ions. Models for the thermoluminescence signals resulting from close association of the dopant recombination sites and the charge traps are discussed. Further consideration of a preference for impurity clustering, in order to reduce lattice strain, is used to explain the concentration and annealing induced changes.