Synthesis, characterization, and thermoluminescence‐based high‐dose neutron and gamma dosimetry study of Al₅BO₉: Mn, Li nanophosphor

Abstract

A near tissue equivalent (Zeff = 10.8) and wide bandgap (Eg = 5.95 eV) Al5BO9: Mn, Li nanophosphor was synthesized by facile gel‐combustion (GC) method, and structural characterizations were performed by XRD, infra‐red, transmission electron microscopy, energy‐dispersive spectra, diffuse reflectance UV–visible spectra, and PL studies. Thermoluminescence (TL) study of Al5BO9: Mn, Li revealed the dosimetry glow peak at 542 K, which was absent in undoped Al5BO9 indicating the importance of Mn dopant. The highest TL response was obtained for the lowest studied dopant concentration (0.1 mol% Mn) that was attributed to the concentration quenching phenomenon. The material is highly reusable with low fading (<10%) up to 110 days. TL response for both thermal neutron and gamma radiations showed excellent linearity within 5 × 109–3 × 1011 n/cm2 and 30–5000 Gy, respectively. These studies suggested promising potential of Al5BO9: Mn, Li nanophosphor in clinical neutron dosimetry and food irradiation dosimetry applications. Based on the variation of calcination temperature, strategy toward dual application, namely, radiation dosimeter and red‐light emitting phosphor of the material was established. For a better understanding of the TL process, various kinetic parameters like activation energy (E), order of kinetics (b), and frequency factor (s) were evaluated using different methodologies, and the results were found to be in good agreement.

Structural and optical properties of Mg1−xMnxP2O6(x = 0–1.0) magnesium metaphosphate

“…Mn 2+ ion has an outer 3d 5 electron configuration, which shows the spin-forbidden 4 T 1 → 6 A 1 transitions in 3d shell. [1][2][3] When Mn 2+ is doped in an octahedral site, it can efficiently give red luminescence ( 4 T 1 → 6 A 1 ) under excitation of near ultraviolet or blue wavelength. Due to the typical d 5 electron configuration, the luminescence properties of Mn 2+ ions are closely related to the crystallographic environment.…”

“…Among the transition metal ions, Mn 2+ is one of the most exciting activators used in luminescence materials. Mn 2+ ion has an outer 3d 5 electron configuration, which shows the spin‐forbidden 4 T 1 → 6 A 1 transitions in 3d shell 1–3 . When Mn 2+ is doped in an octahedral site, it can efficiently give red luminescence ( 4 T 1 → 6 A 1 ) under excitation of near ultraviolet or blue wavelength.…”