UV-Induced Thermoluminescence of Natural Ca-Rich Carbonates

Abstract

The 400 nm-thermoluminescence (TL) emission of UV (254.7 nm) irradiated Ca-rich carbonates of inorganic

(aragonite) and biogenic (mollusc exoskeleton) origin is here reported. The samples exhibit complex

glow curves, but (i) acceptable TL sensitivity when exposed to ultraviolet C (UVC) irradiation and (ii) stability

of the UV-induced TL signal with initial rapid decay (ca. 70% for the aragonite and 40% for the biogenic

carbonate) while maintaining the stability from 75 and 150 hours onwards. The dose response shows

a significant scattered behavior up to 8 hours of UVC exposure, which may be associated with a combination

of the phototransfer TL mechanism, the bleaching process, and the partially ionizing effect of the UVC

irradiation.