Abstract:

The (Ce_0.01Eu_xLu_0.99-x)₃Al₅O₁₂ (x=0.2%, 0.5%, 1%, 2%) scintillating polycrystalline powders were prepared by high temperature solid state reaction method, and the sample structure and luminescence property, especially energy transfer between Ce³⁺ and Eu³⁺, were studied. A pure cubic phase was confirmed in all samples by X-ray diffraction (XRD). X-ray excited luminescence (XEL), photoluminescence excitation and emission spectra (PL) were employed to study the influence of increasing Eu³⁺ concentration on the luminescent property of Ce³⁺ and Eu³⁺ as well as the energy transfer from Ce³⁺ to Eu³⁺. The variation of the integral intensity of luminescence of Ce³⁺ in XEL with increasing Eu³⁺ concentration illustrated energy transfer from Ce³⁺ to Eu³⁺. The luminescence behavior of Ce³⁺ and Eu³⁺ in the host of Lu₃Al₅O₁₂ under UV-visible light was studied by PL, and emission peak of Eu³⁺ under 340 nm excitation of Ce³⁺ directly indicated the energy transfer from Ce³⁺ to Eu³⁺. In addition, thermoluminescence spectra (TL) were utilized to identify the energy transfer from Ce³⁺ to Eu³⁺, and also the shifting of the thermoluminescence peaks with Eu³⁺ concentration increasing, was explained by two paths of the electrons transfering from Ce³⁺ to Eu³⁺ under thermal excitation.

Key words: Lu3Al5O12: Ce, Eu, polycrystals, luminescence property, thermoluminescence, energy transfer