Thermoluminescence behaviour and kinetic analysis of a novel Tb3+-Doped LaCa4O(BO3)3 phosphor: Impacts of heating rates and dose
Küçük Resim Yok
Tarih
2025
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Sci Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This study employs kinetic analysis methods to comprehensively understand the thermoluminescence (TL) behaviour of Tb3+-doped LaCa4O(BO3)3 ( LACOB ), applying the Hoogenstraaten and Booth-Bohun-Parfianovitch methods, as well as the T m-T stop and Glow Curve Deconvolution (GCD) techniques. Optimal TL intensity was found at a Tb3+concentration of 2 wt%, beyond which concentration quenching occurred. The complete TL glow curve before preheating displays two peaks at approximately 70 degrees C and 286 degrees C. After preheating, only the 286 degrees C peak remains, due to its greater stability and intensity, making it the primary TL peak relevant for dosimetric applications. As the heating rate increased, the TL glow peaks shifted to higher temperatures and exhibited reduced intensity due to thermal quenching. The TL intensity exhibited superlinear behaviour at lower doses (0.5-20 Gy), followed by nearly linear behaviour at intermediate doses (30-100 Gy), and sublinear behaviour at higher doses. Anomalous fading of the TL signal was observed in LACOB:2 wt%Tb, suggesting competition with radiationless transitions. Activation energy values derived from Hoogenstraaten and Booth-Bohun-Parfianovitch methods showed close alignment, supporting the reliability of the kinetic analysis. The T m-T stop and GCD analyses with preheating identified four distinct TL glow peaks, with activation energies between 1.72 and 1.82 eV. Analysis whole glow curve revealed nine TL glow peaks overall, ranging from 1.08 to 1.82 eV, reflecting a complex trap structure with continuous energy distributions. The GCD method yielded a Figure of Merit (FOM) of 2.67 % with preheating and 2.84 without preheating, indicating a strong fit between experimental and theoretical data in both cases. The material demonstrated excellent stability and reusability, making it a strong candidate for dosimetric applications.
Açıklama
Anahtar Kelimeler
Thermoluminescence, Kinetic analysis, Glow curve deconvolution, Activation energy, Dosimetric application, LaCa4O(BO3)3
