On the thermoluminescence of LiF from 83 to 320 K

Abstract

Thermoluminescence was studied in LiF (TLD-100) single crystals from 83 to 320 K. In this temperature range, the glow curve presents six peaks at 138, 153, 193, 260, 283, and 300 K and a seventh peak at approximately 240 K. Based on annealing response, linearity, phototransference, and optical bleaching experiments, the glow peak at 138 K was related to VK hole centers, while the remaining glow peaks were associated with electron traps, although a clear relation between the highest temperature glow peak, at 300 K, and electron centers could not be established with certainty. The seven glow peaks emit at three wavelengths, namely, 270, 300, and 420 nm. The emission band at 270 nm is more intense for the glow peaks at 138 and 153 K. For the remaining glow peaks, the emission bands at 300 and 420 nm are the most important ones. The emission band at 270 nm was related to the recombination of VK holes at recombination centers other than the ones normally associated with the emission band at 420 nm. The emission band at 300 nm was related to the recombination of electrons and VK centers. It was verified that the glow peaks at 138, 153, 193, and 260 K obey first order kinetics.