High-sensitivity and wide-linear-range thermoluminescence dosimeter (TLD) is of importance for detecting highdose radiation in industry, medicine, and agriculture as well as materials and food processing. In this work, we synthesize a series of LiMgPO 4 doped with Tm 3+ , Tb 3+ , and B 3+ via a hightemperature solid-state reaction technique. To observe the effect of dopants, we first investigate the structure by Rietveld refinement of high-quality X-ray diffraction (XRD) data and then study the thermoluminescence (TL) properties of samples radiated by β-rays in detail. The TL signal of LiMgPO 4 :Tm,Tb,B is originated from Tm 3+ 4f−4f transitions. The kinetic parameters are obtained through fitting the TL glow curve based on the general-order kinetics model, revealing that the dominant TL peak at ∼323 °C is related to ∼1.49 eV trap. Through constructing the vacuum-referred binding energy (VRBE) scheme, we uncover that this deep trap mainly originates from the Tb 3+ dopant acted as the captured center of free hole. After codoping 0.6% B 3+ , the sensitivity of sample as TLD increases ∼170%. According to the radiation dose-dependent TL intensities, the sensitivity of LiMgPO 4 :Tm,Tb,B is about 200% larger than that of the commercial LiF:Mg,Cu,P at 0.08 Gy, and more sensitive at higher dose. Moreover, the studied sample has wider linear range (up to 10 000 Gy) toward high-dose side, good reproducibility (RSD ∼ 4.6%), and weak fading (∼8% after 34 days), and therefore has potential application as TLD for monitoring high-dose radiation.

The thermoluminescence (TL) spectra and dose responses of strontium sulphate doped with rare earth ions show that the SrSO4:Eu2+ phosphor might reasonably be assumed a isoelectronic trap sample which has unique TL characteristics: there is only one obvious glow peak at 385 nm, 489 K in the TL 3D emission spectra and its TL dose response is linear-sublinear. However, there are several elementary glow peaks in the TL 3D emission spectra and their TL dose responses are linear-supralinear for SrSO4:RE3+ (RE = Dy, Tm). These TL peaks occurred from low to high temperature indicate that the traps are distributed in different energy levels. When a suitable amount of other impurities co-doped into these SrSO4:RE3+, such as phosphorus, the relative intensities of these elementary glow peaks are changed significantly, especially the TL peak ~500 K is enhanced while the peaks at lower temperature are suppressed. The enhanced peak of SrSO4:RE3+,P is attributed to the deep traps. Their dose responses remain in nonlinearity when co-doped phosphorus. The above results and the luminescence properties of other sulphate doped rare earths impurities illustrate that the TL characteristics depend on the structure of defect complexes which can be assumed the basic elements in the TL multi-stage processes.