Structure and gamma attenuation behavior of copper ions in host glass from the system (P2O5–LiF–CaF2)

Abstract

Copper-doped lithium calcium fluorophosphate glasses in the compositional system (60−x)P2O5·20LiF·20CaF2·xCuO (x = 0−3 mol%) were prepared using the conventional melt quenching technique. X-ray diffraction confirmed the amorphous, non-crystalline phase of the glasses. Optical absorption spectra indicated the presence of additional broad visible-NIR absorption bands upon CuO doping, attributed to distorted Cu2+ ions. Possible overlaps from Jahn-Teller distorted sites or clustering into nanodomains may contribute to band broadening. The direct optical bandgap was found to reduce from 3.89 eV to 1.17 eV with increasing CuO content. The study of physical parameters showed almost linear variation in density (2.62–2.95 g/cm3) and molar volume (40.45–35.29 cm3/mol) with incremental CuO substitution, explained by changes in structural packing efficiency and formation of Cu–O complexes. FTIR spectra revealed vibrations corresponding to phosphate structural groups. The simulation of radiation shielding parameters displayed steady improvements with higher CuO fractions, which were related to enhanced photon interactions via photoelectric absorption and Compton scattering.