Observation and partly characterisation of silver nanoparticles in X-ray irradiated radiophotoluminescent phosphate glass

► Direct observation and characterisation of silver nanoparticles in X-ray irradiated phosphate glass were demonstrated. ► Correlations between the Ag + concentration and X-ray-induced silver species were examined. ► Evidence of spherical silver nanoparticles with sizes ranging from 5 to 30 nm was obtained. ► Three-dimensional contour plots using combined excitation–emission spectroscopy were recorded. The direct observation and characterisation of silver nanoparticles or clusters embedded in a Ag +-activated phosphate glass was demonstrated. Correlations between the isolated Ag + concentration and X-ray-induced silver species were systematically examined using optical measurements. Evidence of spherical silver nanoparticles or clusters with sizes ranging from 5 to 30 nm was obtained from the lattice spacings and from energy dispersive X-ray spectroscopy combined with transmission electron microscopy. Three-dimensional contour plots using combined excitation–emission spectroscopy were also recorded to allow identification of the complicated spectroscopic features of the sample.