RESUMO
A facile and productive method has been developed to synthesize uniform LaF3 nanocrystals with controllable shapes, including polyhedrons, nanorods and nanoplates. By tuning the amount of NaOH and ligands (oleic acid and octadecylamine), we can finely tailor the shapes and sizes of LaF3 nanocrystals. Three prepared LaF3 nanostructures were well characterized, followed by a series of control experiments to propose a mechanism for the shape control. Based on the success in materials synthesis, controlled patterning of LaF3 nanoplates on substrates has also been achieved. After Yb/Er or Yb/Tm was co-doped in these LaF3 nanostructures, they could serve as nanoparticulate host matrices to give strong upconversion luminescence, showing great potential in biomedical applications considering their small sizes and well-defined shapes.