Synthesis of NaYF₄ Nanocrystals with Predictable Phase and Shape

In this Full Paper, a water/alcohol/oleic acid system was developed to prepare NaYF 4 nanocrystals with predictable size, shape and phase. The structural and kinetic factors that govern the phase and shape evolution of NaYF 4 nanocrystals have been carefully studied, and the influence of NaF to Y 3+ ratio, reaction time and temperature on the phase and shape evolution of the as‐prepared NaYF 4 samples was systematically investigated and discussed. It was found that the NaF to Y 3+ ratio was responsible for the shape evolution while temperature and reaction time was the key for the phase control of the NaYF 4 nanocrystals. This study would be suggestive for the precisely controlled growth of inorganic nanocrystals, especially for those usually crystallizing in diverse crystal structures.