Abstract: (Y,Gd)BO³∶Eu powders were prepared with the conventio nal solid-reaction method. Surface-modified (Y,Gd)BO₃∶Eu powders with MgF₂ were prepared by the emulsion method. The best preparing wa y is that MgCl₂ was dropped to the mixture of NH₄F and (Y, Gd)BO₃∶Eu powders to prepare surface-modified (Y,Gd)BO₃ ∶Eu powders. The interaction between F^- ions and the phosph or particles was discussed. The structures of surface-modified (Y,Gd)BO_{3∶Eu powders were measured by XRD, IR, excitation spectra and emission spectra.}

Key words: (Y,Gd)BO₃∶Eu, phosphor, coated, MgF₂, excitat ion spectrum, emission spectrum