Luminescence and energy transfer of rare-earth-metal ions in Mg2Y8(SiO4)6O2

Abstract

The photoluminescence of Ce³⁺, Tb³⁺ and Sm³⁺, and energy transfer from Ce³⁺ to Tb³⁺, Dy³⁺ and Sm³⁺ in Mg₂Y₈(SiO₄)₆O₂ are reported and discussed. The Ce³⁺ ion shows blue luminescence under UV excitation, and occupies simultaneously the 4f site and 6h site in the host lattice. The optimum concentrations for the ⁵D₃ and ⁵D₄ emissions of Tb³⁺ and the ⁴G_5/2 emission of Sm³⁺ are determined to be 0.04, 0.20 and 0.10 mol in every mol of Mg₂Y₈(SiO₄)₆O₂, respectively. The critical distances responsible for the cross-relaxation between the ⁵D₃–⁵D₄ and ⁷F₆–⁷F₀ transitions of Tb³⁺ and between the ⁴G_5/2–⁴F_9/2 and ⁶H_5/2–⁴F_9/2 transitions of Sm³⁺ are estimated to be 1.43 and 1.06 nm, respectively. Both Tb³⁺ and Dy³⁺ can be sensitized by Ce³⁺, but Ce³⁺ and Sm³⁺ quench each other.