Thermoluminescent glow curve of GdREAlO (RE=Dy or Pr) beta irradiated phosphors.

Phosphors composed of GdREAlO (0≤x ≤ 5 RE = Dy or Pr) stoichiometries were synthesized using the reverse coprecipitation pathway. The thermoluminescent responses of all phosphors were studied under beta radiation exposure. Doping the gadolinium aluminate host improved the thermoluminescent response of the phosphors, with the phosphors composed of GdDyAlO and GdPrAlO being the most sensitive. The Dy ions produced a higher improvement of the thermoluminescent signal than the Pr ions. Additionally, a proportional relationship between the similarity of the atomic numbers of the dopant and replaced ions and the sensitivity to thermoluminescence was confirmed. Besides, a slight shift of the thermoluminescent peaks toward lower temperatures was detected for doped phosphors. In the repeatability tests applied to the phosphor composed of GdDyAlO, an anomalous increase in sensitization was observed. The observed sensitization was associated with the formation of electron trap clusters resulting from the continuous exposure to beta radiation. Furthermore, another sensitization phenomenon was detected in the phosphor with GdPrAlO stoichiometry when it was heated at low temperatures. The aforementioned striking behavior was related to quasi-continuous distributions of electron traps and the tunneling effect. In regard to linearity, the phosphor composed of GdDyAlO exhibited a linear response with the dose across the entire range of beta doses. However, the response of the GdPrAlO phosphor lost linearity beyond 26.4 Gy of beta dose. The results obtained through the use of the T-T method and deconvolutions suggested an enhancement in the efficiency of the thermoluminescent mechanisms due to the incorporation of activators.