Synthesis, Characterization, and Optical Properties of Ytterbium(III) Phosphates and Their Incorporation in Different Glass Matrices

Nanosized hydrated YbPO₄·nH₂O powders were prepared by precipitation from aqueous solutions. It is shown that the structure, optical properties, and size of the raw particles can be further tailored by the subsequent calcination. The raw hydrous crystals transform into the anhydrous YbPO₄ xenotime form after calcination at temperatures above 800 °C. In comparison with the hydrous form, the latter is characterized by a well-defined defect-free xenotime structure and multiple sharp peaks in the absorption and emission bands due to the splitting of Yb³⁺ ²F₇/₂ and ²F₅/₂ manifolds into multiple Stark sublevels as well as by a significant increase in the near-infrared photoluminescence intensity. It is demonstrated that the synthesized YbPO₄ phosphors can withstand the corrosive behavior of phosphate glass melts; their reaction with silica glass at temperatures up to 2000 °C is negligible, and thus, YbPO₄ particles can be used to prepare translucent glass–crystal composites.