4F-5D EXCITATION ENERGY OF TB3+ IN SOLIDS

Excitation spectra of the 5D4→7F emission of Tb3+ were measured in Sc(or In)BO3, Y (or Gd)BO3, Y3Ga5O12, Sc (or Y)PO 4, and Sc2(or Y2)O3 at room temperature. The 4f-5d excitation band is discriminated from the host lattice excitation band by inspecting the concentration dependences of the excitation spectra. The energy and the shape of the 4f-5d excitation band are almost the same in the lattices with the same structure. The band splittings are related to the symmetry of the crystalline field acting on Tb3+. The 4f-5d excitation band is extremely enhanced by lowering temperature to 77°K.