Enhance optically stimulated luminescence sensitivity and improve fading of newly developed LiMgPO4:Er phosphor

Abstract

To avoid fading, the readout time of the old LiMgPO₄:Er in the previous study had to be taken to be at least 20 s. The readout time is up to 20 s, which not only contradicts the fast OSL readout, but also eliminates too many OSL signals per readout and is not favourable to the requirement that the OSL can be read multiple times. The primary objective of this study is to reduce readout time under conditions where the OSL signal of LiMgPO₄:Er phosphor stabilizes after irradiation. The OSL properties were investigated. To achieve OSL fading of about 5% within 30 d after irradiation, the shortest integration time for new LiMgPO₄:Er in this study was 1 s, whereas old LiMgPO₄:Er required 20 s. When the integration time was 1 s, the OSL sensitivity of the new LiMgPO₄:Er samples in this study was about 2.4 times that of the old LiMgPO₄:Er samples. A new LiMgPO₄:Er phosphor with an OSL signal loss of about 5% for the shortest integration time of 1 s within 30 days after irradiation, a sensitivity comparable to that of TLD-500k, and an MMD as low as 38 μGy was successfully prepared, which will meet the fast read out and the multiple readings requirements.