Preliminary study of CeF3 concentration-dependent luminescence and synchrotron X-ray imaging of La2O3–ZnO borophosphate glasses

Abstract

Ce3+-activated borophosphate glasses have attracted interest as luminescence materials for synchrotron X-ray imaging because their optical and emission properties can be tailored through compositional control. This preliminary study aimed to characterize the CeF₃ concentration-dependent luminescence of La2O3–ZnO borophosphate glasses and to evaluate the feasibility of synchrotron X-ray image formation. Glasses with compositions of 10La2O3–20ZnO–5B2O3–(65−x)P2O5–xCeF3 (x = 0.00–1.00 mol%) were prepared by conventional melt-quenching method. The effects of CeF3 concentration on the physical, structural, optical, luminescence, photon attenuation, and imaging properties were investigated using density and refractive index measurements, X-ray diffraction, UV-Vis-NIR spectroscopy, photoluminescence (PL), radioluminescence (RL), PL decay analysis, theoretical mass attenuation coefficient calculations, and synchrotron X-ray imaging. All glasses were amorphous and transparent in the visible region, and their density increased with CeF3 content. The glass containing 0.10 mol% CeF3 showed the highest PL and RL intensities; higher concentrations reduced the emission intensity, consistent with concentration quenching. The luminescence spectra exhibited a broad near-ultraviolet band attributed to the allowed 5d→4f transitions of Ce3+. The 0.10 mol% CeF3 glass showed an intensity-weighted average PL lifetime of 24.76 ns under pulsed optical excitation, consistent with the fast 5d→4f emission of Ce3+; this value characterizes the PL decay and should not be interpreted as a scintillation timing parameter. The calculated mass attenuation coefficients varied slightly over 0.001–1 MeV, indicating that CeF3 incorporation had minimal influence on photon attenuation. Under 11.5 keV monochromatic synchrotron X-rays, the imaging configuration employing the 0.10 mol% CeF3 glass achieved an MTF-derived spatial resolution of 44.43 lp/mm at MTF = 0.2. Successful image formation provides preliminary evidence supporting further investigation of this glass for X-ray imaging, although practical application requires further validation.