Some Consequences of the InductionResonance Theory of Nonradiative Transitions

摘要

For the example of the ions of rare-earth elements and transition metals in solutions, glasses, and crystals, it is shown that the conclusion of the induction–resonance theory of nonradiative transitions concerning the constancy of the quantity kr(knrn4a3)1 (where kr is the rate constant of a radiative transition, is the overlap integral of the normalized luminescence spectrum with the vibrational spectrum of absorption of promoting–accepting molecular groups that surround the ion, C is the molar concentration of these groups, knris the rate constant of a nonradiative transition from the same level, n is the refractive index of a medium, and a is the radius of a sphere around the ion that does not contain the promoting–accepting groups) is valid for electric-dipole electronic transitions. Values of this quantity are constant to within an order of magnitude, whereas the rate constant of the nonradiative transition changes by eight orders of magnitude. Deviations from this regularity indicate that the nature of the radiative transition is related to the magnetic dipole or the electric quadrupole rather than to the electric dipole.