Synthesis and upconversion emission of rare earth-doped olive-like YF3 micro-particles

The olive-like YF₃ micro-particles were fabricated via a two-step route. The precursor NH₄Y₃F₁₀ nano-cages sized 8 nm with hollow interiors were first synthesized in a solid reaction at room temperature. In the course of subsequent hydrothermal treating, the unstable NH₄Y₃F₁₀ nano-cages were decomposed, resulted in the formation of Y(OH)_1.63F_1.37 micro-tubes. Prolonging the hydrothermal reaction induced the further decomposition of Y(OH)_1.63F_1.37 to produce YF₃ nano-crystals, which then aggregated together forming the final olive-like YF₃ micro-particles. For the Er³⁺/Yb³⁺ co-doped olive-like YF₃ micro-particles, intense visible upconversion emissions were measured under 976 nm excitation owing to the partition of rare earth ions in the lattice, indicating this material a promising luminescent host.