Thermoluminescence and anomalous heating-rate behavior in SmBa3B9O18: Evidence for hierarchical trap distribution and strong retrapping dynamics
Applied Radiation and Isotopes, cilt.236, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 236
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.apradiso.2026.112765
- Dergi Adı: Applied Radiation and Isotopes
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, EMBASE, INSPEC, MEDLINE, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Anomalous heating-rate behaviour, SmBa3B9O18, Tm–Tstop analysis, Trap hierarchy
- Çukurova Üniversitesi Adresli: Evet
Özet
SmBa3B9O18 nanostructures were synthesized by a sol–gel assisted microwave combustion route and subsequently calcined at 800 °C, yielding a crystalline rare-earth-based borate host lattice for detailed thermoluminescence (TL) characterization. X-ray diffraction and Rietveld refinement confirm the formation of a single-phase structure with high crystallinity and well-defined lattice parameters. TL measurements recorded in a 565 nm band-pass detection window reveal well-resolved multi-peak glow curves suitable for detailed kinetic analysis. Preheating at 150 °C for 8 s effectively removes shallow traps and stabilizes the dosimetric signal, yielding dominant glow peaks at ∼220 °C and ∼290 °C associated with thermally stable trapping centers. The material shows a nearly linear dose response up to ∼60 Gy, followed by controlled supralinearity up to 500 Gy, together with a low minimum detectable dose (∼0.13 Gy) and excellent reusability, with cycle-to-cycle deviations within ±5%. Variable heating-rate experiments (0.2–4 °C s−1) reveal pronounced anomalous heating-rate behavior, where both peak intensity and integrated TL signal increase with heating rate, deviating from conventional kinetic models. Combined various-heating-rate, Tm–Tstop and initial-rise analyses (with thermal-lag correction) yield activation energies of ∼1.6–1.7 eV and ∼1.9–2.0 eV for the main peaks and reveal characteristic plateau–shift behavior consistent with a hierarchical trap system comprising multiple overlapping and partially distributed trapping levels. Fading analysis shows non-monotonic behavior, with an initial TL increase of up to ∼20% around 12 h followed by gradual decay, attributed to post-irradiation charge redistribution and thermally assisted retrapping within a coupled trap system. These results demonstrate that SmBa3B9O18 is a promising TL dosimetric material, combining high structural stability, sensitive and reusable response, and complex non-classical luminescence kinetics governed by coupled trap–recombination dynamics.