Synthesis of oil-dispersible hexagonal-phase and hexagonal-shaped NaYF4:Yb,Er nanoplates

Oil-dispersible alpha-NaYF4 spherical nanoparticles and beta-NaYF4 hexagonal-shaped nanoplates were synthesized by the liquid-solid two-phase approach at different reaction temperatures. The TEM and FE-SEM images reveal that the nanoplates have a relatively narrow size distribution. In comparison with other methods, pure beta-NaYF4 hexagonal-shaped nanoplates were prepared under a relatively mild condition. The nanoplates grew at the liquid-solid interface with slow crystallization rate, which may be preferable for achieving beta-NaF4.