Double perovskites have become a research hotspot in recent years due to their flexible structure, easy doping, and good thermal stability. Photoluminescence (PL) of rare-earth-doped double perovskite materials has been frequently reported, but few studies on thermoluminescence (TL) have been conducted.

This study aims to investigate the TL characteristics of Y_2-x-yBi_xEu_yMgTiO₆ (0≤x<1, 0≤y<1) phosphors.

Bi³⁺ and Eu³⁺ co-doped Y₂MgTiO₆ samples were synthesized by a high-temperature solid phase method, and the X-ray diffraction (XRD), PL, and TL of the samples were measured.

XRD analysis results show that the crystal structures of all samples are monoclinic P2₁/n, and Bi³⁺ and Eu³⁺ are doped into Y₂MgTiO₆ by substituting Y³⁺. The PL results show that Y_1.79Bi_0.01Eu_0.20MgTiO₆ has a strong red emission near 620 nm (corresponding to the ⁵D₀→⁷F₂ transition of Eu³⁺), which is accompanied by a long afterglow. The TL curves of the samples doped with different concentrations of Bi and Eu ions show that Y_1.79Bi_0.01Eu_0.20MgTiO₆ has the highest TL sensitivity, and the samples exhibits two significant TL peaks near 510 K and 610 K. The TL spectrum is more abundant than the fluorescence spectrum, and the ⁵D₀→⁷F_J (J =1,2,3,4) transition of Eu³⁺ can be observed. The TL intensity of the sample has a good linear relationship with the irradiation dose in the range of 2~1 000 Gy. The TL kinetic parameters of the samples are analyzed using two methods under different preheating temperatures (T_m and T_stop) and glow curve deconvolution. The analysis results show that the depth of the TL trap in the sample extends from 0.80 eV to 1.40 eV.

The results of this study indicate that the TL spectrum is richer than the PL spectrum and that Y_1.79Bi_0.01Eu_0.20MgTiO₆ may be used as TL dosimeter material for large dose detection.