High-Sensitivity and Wide-Linear-Range Thermoluminescence Dosimeter LiMgPO₄:Tm,Tb,B for Detecting High-Dose Radiation

Abstract

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.

Manipulation of Shallow-Trap States in Halide Double Perovskite Enables Real-Time Radiation Dosimetry

“…As shown in Figure A, compared with the case with no X-ray irradiation, significant TL phenomena are observed under incremental irradiation dosages, demonstrating that X-rays create substantial traps within 0.005 Ag + @ Cs 2 NaInCl 6 . Furthermore, a broad band located at 248.5 K was recorded in the TL curves, implying that X-rays solely generate one type of trap state in 0.005 Ag + @ Cs 2 NaInCl 6 . In addition, Figure B shows the integral area of the TL curve dependency on the received dosage, indicating that the trap concentration is highly correlated to the irradiated dosage.…”

“…Furthermore, a broad band located at 248.5 K was recorded in the TL curves, implying that X-rays solely generate one type of trap state in 0.005 Ag + @ Cs 2 NaInCl 6 . 42 In addition, Figure 2 B shows the integral area of the TL curve dependency on the received dosage, indicating that the trap concentration is highly correlated to the irradiated dosage. The above results directly illustrate that a new storage phosphor has been designed in the halide double perovskite 0.005 Ag + @ Cs 2 NaInCl 6 .…”

Dosimetric and spectroscopic study of LiMgPO4 doped with Tm3+ and Er3+

“…For the Tm-doped LMP phosphor, the TL low-temperature peak is strong, and the high-temperature peak is weak. 60 However, the high-temperature peak of LMP:Tm,Er is clearly more intense than the low-temperature peak, which indicates that the double-doped sample inhibits the shallow trap signal of the low-temperature peak and enhances the deep trap signal, which enhances the stability of the sample signal. Despite the nonradiative deexcitation of erbium ions, the sample exhibited high TL and OSL output.…”

Photoenergy Conversion Behaviors of Photoluminescence and Photocatalysis in Silver-Coated LiBaPO4:Eu2+

“…Generally, photoluminescence occurs inside a semiconductor, whereas photocatalysis occurs on the outer surface. Phosphors can emit different wavelengths after light excitation (i.e., photoluminescence is a light-to-light photoenergy converter). , Meanwhile, photocatalysts absorb an incident photon and accelerate chemical redox reactions on surfaces (i.e., photocatalysis is a light-to-chemical photoenergy converter). , …”

“…1,2 Meanwhile, photocatalysts absorb an incident photon and accelerate chemical redox reactions on surfaces (i.e., photocatalysis is a light-to-chemical photoenergy converter). 3,4 Under light irradiation with an energy equal or above that of the band gap, an electron can be promoted to an excited state from a valence band (VB) to a conduction band (CB), creating a hole in the former. Consequently, the excited electrons face several possible results.…”