Synthesis of Eu³⁺ doped Gd₂O₃-HfO ₂ nanopowder for radiation detection

A novel heavy phosphor, europium doped Gd₂O₃-HfO ₂ nanopowders, were successfully prepared via a co-precipitation method. Particles of as-prepared powders are spherical in shape and have an average particle size of 50 nm in diameter. X-ray diffraction measurement confirms the formation of the cubic phase in the Gd₂O ₃-HfO₂ solid solution. Photoluminescence spectra of Eu³⁺ doped Gd₂O₃-HfO₂ nanopowder (λ_ex = 250 nm) showed red emission at 611 nm which corresponds to the ⁵D₀-⁷F₂ transition of Eu³⁺ ion. A 1 mol% Eu doped powder show highest luminescence, however the phosphors show lower quenching concentration, 5 mol% Eu³⁺ doped sample exhibits very weak luminescence.