Optical and physical characteristics of HBLAN fluoride glasses containing cerium

Abstract

The optical and physical characteristics of HBLAN fluoride glasses containing cerium have been studied using a variety of techniques. These stable glass compositions have been considered as candidates for electromagnetic particle detectors due to their high density (5.77 g cm −3), high average atomic number and scintillation properties. Optical fluorescence measurements on glass samples containing different concentrations (5% and 8%) of cerium show the characteristic emission spectrum of cerium in a fluoride environment. Replacing the hafnium with zirconium quenched the fluorescence almost completely. The lowest exciton level ( E 0) for the HBCeAN glass samples was measured to be 4.39 ± 0.01 eV. XPS scans of these glass samples showed that the strong lines from hafnium, and oxygen present as an impurity, obscure the valence band energy levels of cerium. The refractive index, as a function of wavelength was measured in the visible region and fitted with a Sellmeier formula. Abbe numbers of 68 and 56 were calculated for HBLAN glasses containing cerium and lanthanum respectively. These glasses are promising candidates for fast, radiation-resistant scintillator elements in electromagnetic calorimeters used at high energies.