The influence of gamma radiation on the structure of solid solutions of CaF2:SrF2:YbF3 crystals and ceramics

The structure of laser ceramics based on CaF 2 :SrF 2 :YbF 3 has been studied and compared with that of single crystals of the same composition when exposed to gamma radiation from a 60 Co source. Both the crystal and ceramic samples, composed of 65 % CaF 2 , 30 % SrF 2 and 5 % YbF 3 , were found to possess a cubic fluorite structure corresponding to the Fm-3m space group. Interestingly, lattice parameters varied across different regions within a single sample, despite maintaining a uniform ytterbium concentration throughout. These findings suggest the occurrence of local structural irregularities or defects during the crystal growth stage. Comparative analysis revealed that ceramics exhibited slightly more structural inhomogeneity than single crystals, likely due to grain boundary effects. X-ray diffraction and electron microscopy were used to assess microstructural changes, supporting the hypothesis of radiation-induced lattice strain. These findings provide important insights for the development of radiation-resistant laser materials and highlight the structural stability of mixed fluorides under gamma exposure. • XRD shows CaF₂–SrF₂–YbF₃ crystals and ceramics have pure fluorite cubic phase with no impurities. • Lattice variation along boule due to Ca²⁺/Sr²⁺ competition, increasing spacing with Sr content. • γ-irradiation equalizes lattice in crystals by breaking Yb clusters; ceramics less affected • Radiation alters lattice via Yb³⁺ valence shifts; crystals respond stronger than ceramics