Ligand dynamic effect on phase and morphology control of hexagonal NaYF4†
In this work, the ligand dynamic effect was utilized to synthesize hexagonal NaYF4 (β-NaYF4) crystals with controllable morphology by a hydrothermal method. A series of fatty acids was chosen as organic ligands to investigate the ligand dynamic effect on the crystal morphology. Confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray power diffraction (XRD), the dynamic nature of ligands has strong influences on the crystal morphology, crystal growth and phase transition processes. Moreover, possible crystal growth processes with different chain length ligands have been proposed.