Potassium sodium tartrate-assisted hydrothermal synthesis of BaLuFs ：Yb3＋/Er3＋ nanocrystals

Highly-dispersed BaLuFs：yb3＋/Er3＋ nanocrystals were prepared by a facile potassium sodium tartrate- assisted hydrothermal method. The average particle size was approximately 20-25 nm. The formation mechanism is discussed. Potassium sodium tartrate led to form a complex with an approximately three- dimensional network structure, which insured largely concurrent nucleation. As a result, we acquired uniform nanoparticles. The hydrothermal temperature, holding time, and pH value were important fac- tors affecting the formation of the BaLuF5 ：yb3＋/Er3＋ nanocrystals. We investigated their influence on the formation and realized the optimal reaction parameters. Remarkably, potassium sodium tartrate also con- tributed to the biocompatibility and potential biomedical applications of BaLuFs ：Yb3＋/Er3＋ nanocrystals by decomposing into small organic groups attached to the nanoparticles.