Ion beam induced luminescence of lanthanide complexes in organic solvents irradiated by hydrogen and argon ion beams

In this study, the structures of lanthanide complexes in organic solvents for minor actinide recovery were evaluated by measuring ion beam induced luminescence (IBIL) of lanthanide complexes with organic solvents using H⁺ and Ar⁸⁺ ion beams. The organic solvent types affected the IBIL spectrum shapes of the lanthanide complexes in the measurements. The shapes of the IBIL spectra of lanthanide complexes in the organic solvent under Ar⁸⁺ ion beam impact were found to be similar to those with the H⁺ ion beam. Additionally, the organic solvent samples were compared with the adsorbent samples to evaluate the spectral shapes of the IBIL. The IBIL spectra of the Eu complexes in the N,N,N’,N’-tetraoctyl diglycolamide (TODGA) solvent recorded with ion beams were found similar in shape to that of the adsorbent. However, the IBIL spectrum of Eu complexes differed in the bis(2-ethylhexyl) hydrogen phosphate (HDEHP) solvent and the HDEHP/SiO₂-P adsorbent. Although Eu³⁺ chemically binds to the O of NO₃⁻ in the TODGA solvent, Eu and HDEHP complexes do not contain NO₃ and Eu³⁺ directly binds to the HDEHP solvent. Therefore, the differences in the Eu complex structures might affect the IBIL spectra in the organic solvent and the adsorbent between HDEHP and TODGA.