Energy Transfer Between Rare-Earth Ions

Fluorescence quenching effects caused by multipolar energy-transfer interactions between rare-earth ions are examined. Transfer between remote ions by way of transitions that are matched in energy appears to be essentially dependent upon concentration alone (e.g., Sm3+ self-quenching) while transfer by non-resonant mechanisms can show a strong dependence upon crystal structure (e.g., Eu3+ self-quenching). Examples of thermally dependent multipolar transfer interactions are also given.