Temperature Variation of the Eu²⁺-Luminescence in the Alkali Halides

Abstract

The temperature dependence of the emission spectrum of europium-activated NaCl, KCl, RbCl, KBr, KI, and RbBr has been measured in the temperature range 77–600 K. From these data the activation energy corresponding to the thermal quenching of the Eu-luminescence, as well as the vibrational frequency interacting with the center in its excited state have been determined for each crystal.