Mechanisms of Energy Transfer Involving Trivalent Tb and Pr

The self-quenching of Tb emission, from the Tb5D3 manifold; the self-quenching of Pr emission, from the Pr3P0 manifold; and transfer from Tb5D3 or Tb5D4 to Pr involves dipole—quadrupole interactions in the scheelites. The lifetime for emission from Pr3P0 or Pr1D2 under dilute conditions is very short (∼5 μsec) compared to that for Tb5D3 (∼200 μsec) or Tb5D4 (∼565 μsec). Less than 1% of the excitation transferred from Tb to Pr appears as emission from Pr.