Lb. Shaw et al., MEASUREMENT OF UP-CONVERSION ENERGY-TRANSFER PROBABILITIES IN HOY3AL5O12 AND TMY3AL5O12, Physical review. B, Condensed matter, 50(10), 1994, pp. 6609-6619
The probabilities for up-conversion involving two nearest-neighbor Ho3
+(I-5(7)) ions and Tm3+(F-3(4)) ions in Y3Al5O12 have been determined.
The final states are I-5(5) and I-5(6) for Ho3+ and H-3(4) and H-3(5)
for Tm3+. A rate-equation model has been used to obtain an expression
for the concentration dependence of the up-conversion-rate constant i
n the migration-limited regime. We have also measured the reverse cros
s-relaxation probabilities for two of the processes with Ho3+(I-5(5))
and Tm3+(H-3(4)) as donors. The resuits fit well to the energy-gap law
for phonon-assisted energy transfer. They also show evidence that the
re may be a correlation between the deviations from the energy-gap law
for opposite processes.