Routes to Chemical Modification of the Surface of Nanosized Fluorides

In the investigation EuF₃ nanoparticles modification method is proposed. Ligand-assisted synthesis of RE fluorides makes it possible to obtain stable colloids of surface-modified nanoparticles. This method gives products with higher values of coordinated ligand surface density and can be also used to control the nanoparticle size and shape. Formation of a chemical bond between the ligands and metal ions is shown by IR and luminescence spectroscopies. It is shown that surface modification is a way to enhance the luminescence. EuF₃ nanoparticles modified with Dbm and Phen have intense luminescence, with red emission at ~612 nm prevailed. It is shown that energy transfer from the coordinated Phen and Dbm to Eu³⁺ ions in the surface complexes makes a main contribution to the luminescence intensity increase.