Influence of defects on thermoluminescence in pristine and doped LiMgPO4

Abstract Pure and terbium-doped lithium-magnesium phosphate LiMgPO4 was investigated with respect to its thermoluminescent properties. The samples were synthesized by solid state, ultrasonic spray pyrolysis, as well as by melting and quenching methods. To predict the terbium site, ab initio calculations were carried out. Additional treatment in atmospheres with different oxygen partial pressures was used. The larger is the concentration of oxygen in the atmosphere and, accordingly, the smaller is the quantity of surface oxygen vacancies, the greater is the intensity of thermoluminescence. For a better understanding of thermoluminescence in LiMgPO4 and LiMgPO4:Tb, the TL spectra were recorded. It was concluded that the thermoluminescence of LiMgPO4:Tb is additively composed of the signals of the matrix and activator ions.