Abstract
The luminescence properties of the system Na(Gd,S,Tb)SiO4 (S = Ce3+ or Bi3+) are reported, for the orthorhombic olivine modification as well as for the tetragonal NaF-stabilized modification. The Tb3+ luminescence can be sensitized by Ce3+, Gd3+ or Bi3+. The efficiencies of the several processes are discussed.
