Physical Review LettersIon-Pair Resonance Mechanism of Energy Transfer in Rare Earth Crystal FluorescenceF. Varsanyi, G. H. DiekePublished Dec 15, 1961• 239 citationsPublisherAbstractReceived 22 November 1961DOI:https://doi.org/10.1103/PhysRevLett.7.442©1961 American Physical SocietyDOI10.1103/physrevlett.7.442