Colloidal Synthesis of Luminescent Rhabdophane LaPO4:Ln3+·xH2O (Ln = Ce, Tb, Eu; x(almost equal)0.7) Nanocrystals

Lanthanide phosphate nanocrystals exhibiting the rhabdophane-type structure and mean particle sizes below 10 nm are synthesized by hydrolysis of an aqueous mixture of sodium tripolyphosphate (Na5P3O10) and lanthanide salts. 31P NMR studies show that polyphosphate groups act both as a source of orthophosphate and as complexing agents to, respectively, crystallize and stabilize LnPO4·xH2O (x(almost equal)0.7) nanoparticles. In the ternary system (Ln = La, Ce, and Tb), polyphosphate-capped particles form well -dispersed and highly luminescent aqueous colloids which are promising for applications in light-emitting devices.