Morphology and phase selective synthesis of EuF3 nanostructures by polyelectrolyte assisted chemical reaction and their optical properties

A polyelectrolyte assisted chemical approach has been developed to synthesize well-dispersed EuF3 nanostructures with the controlled morphology and crystalline phase. It is indicated that the hexagonal doughnut-like EuF3 nanostructures with diameters of 200-300 nm have been spontaneously transformed into orthorhombic spindle-like EuF3 nanostructures with diameters of 100 nm and lengths of 250-400 nm with the extension of the reaction time. The negatively charged polyelectrolyte such as sodium poly(styrenesulfonate) (PSS) plays the critical role for the morphology and crystalline phase transformation of EuF3. Moreover, the different EuF3 nanostructures have been characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL). Finally, the formation mechanism of the different EuF3 nanostructures has been primarily discussed.