Temperature Dependence of the Eu3+ Ion Luminescence Lifetime Exhibited by Anhydrous EuCl3

Abstract

Recently, Chen et al. have discussed the effects of slight variations in temperature on the luminescence lifetime of the Eu3+ ion in anhydrous EuCl3. In that work, the luminescence lifetime exhibited a continuous exponential decrease with a linear increase in temperature. However, a limited number of data points were employed, and the range of temperatures was limited to between 293 and 368 K. Attempts to expand the study of anhydrous EuCl3 to temperatures above 368 K resulted in irreversible alterations in the sample (e.g., chemical reaction with its container or structural phase transition), which precluded studies of the sample at higher temperatures. Investigations of the luminescence lifetime below 293 K had not been carried out previously because it was expected that the exponential trend would continue. This assumption appeared to be well founded, since compositional and/or structural variations in anhydrous EuCl3 have not been reported in this temperature range. We have now determined that the previously established trend has not continued and report here the extended thermal dependence of the Eu3+ ion luminescence lifetime in anhydrous EuCl3, at temperatures below 293 K.