RE3+ pairs in garnets and sesquioxides

Abstract Several aspects of the RE 3+ pairs effects in garnets and sesquioxides, such as static and dynamic spectral features and their nature are analyzed. The data on Nd 3+ , Eu 3+ , Er 3+ or Yb 3+ pairs in YAG or Y 2 O 3 are especially discussed. Data showing that the ionic radii misfit between RE 3+ and replaced host ion leads to the spectral shifts of pair satellites from the isolated ion lines and even to anisotropic effects are presented. Although the direct ion–ion short-range magnetic (superexchange) interactions have a strong effect on the emission decay of the pairs, their static effects are relatively small in these lattices. The data on energy transfer in RE 3+ pairs of similar or different centers (in the case of sesquioxides) or cooperative processes and the characteristics of ion–ion interactions function on ion, transitions and matrix are discussed.