Thermoluminescent Centers in MgO Single Crystals

Abstract

The effects of Cr³⁺ and Fe³⁺ impurity concentrations on the kinetics order of the first glow peak of thermoluminescence in MgO single crystals have been examined. It was found that the concentration of Cr³⁺ ions affected the kinetics order of the red component of the luminescence and that of the Fe³⁺ ions the blue one. When these impurity concentrations are relatively low, the second order kinetics is expected, while with increasing concentration the kinetics order should decrease and become the first order. Several such examples have been observed for both red and blue emissions. This may support the consideration that the Cr³⁺ and Fe³⁺ ions work as the luminescent centers for red and blue emissions, respectively. The annealing temperature before irradiation is considered to control the valence conversion of the impurities.