| Title |
Structure and UV emission characteristics of Gd3+-activated X2P2O7 (X = Ca, Sr, Ba) pyrophosphates |
| Authors |
Salnajs, Didzis ; Nilova, Dace ; Stadulis, Jonas ; Sarakovskis, Anatolijs ; Žarkov, Aleksej ; Antuzevics, Andris |
| DOI |
10.1016/j.matchemphys.2026.132800 |
| Full Text |
|
| Is Part of |
Materials chemistry and physics.. Lausanne : Elsevier B.V.. 2026, vol. 363, art. no. 132800, p. [1-11].. ISSN 0254-0584. eISSN 1879-3312 |
| Keywords [eng] |
Gd3+ ; pyrophosphates ; UV emission ; afterglow ; long-lasting luminescence ; thermoluminescence ; Electron spin resonance (ESR) ; radiation-induced radicals |
| Abstract [eng] |
Ultraviolet-emitting phosphors deliver higher-energy photons than visible or infrared sources, which is a prerequisite for efficient photoionisation and energy transfer processes. In this work, gadolinium-activated alkaline-earth pyrophosphates (X2P2O7, X = Ca, Sr, Ba) are comparatively investigated to determine how host composition and structure influence Gd3+ incorporation, irradiation-induced defect formation, and UV-B persistent luminescence characteristics. Reflection electron energy-loss spectroscopy (REELS) indicates that all compounds possess suitable bandgap values for UV emission. X-ray diffraction (XRD) and electron paramagnetic resonance (EPR) analyses confirm successful incorporation of Gd3+ ions at low-to-moderate doping concentrations into the X2P2O7 hosts. All materials exhibit the characteristic Gd3+ 6P7/2 → 8S7/2 UV-B photoluminescence emission at 312 nm, which is also observed in thermally stimulated luminescence (TSL) measurements following X-ray excitation, with each host showing distinct glow peak temperatures. Spin-Hamiltonian parameters derived from EPR spectra simulations reveal that X-ray irradiation induces the formation of oxygen-related hole centres and phosphorus-related radicals. Among the studied compounds, Sr2P2O7: Gd3+ exhibits optimal trap depths for intense UV-B persistent luminescence, maintaining radiance above 5 ⋅ 10−4 mW m−2 sr−1 for nearly 2 h after excitation. These results establish Gd3+-doped pyrophosphates as efficient UV-B phosphors with tuneable defect structures suitable for phototherapy, sterilisation, and photocatalytic applications. |
| Published |
Lausanne : Elsevier B.V |
| Type |
Journal article |
| Language |
English |
| Publication date |
2026 |
| CC license |
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