Cooperative quenching: experiment, theory and Monte-Carlo computer simulation

Abstract

An analytical expression and results of Monte-Carlo computer simulations are proposed for the kinetics of cooperative static quenching decay in crystals with arbitrary acceptor concentration and arbitrary multipolarity of interaction process S=6, 8, 10, which at a long decay time can be approximated by the nonexponential law I( t)exp[−( wt) k ], where k=0.41, 0.3, 0.25 for multipolarities S=6, 8, 10, respectively. The phenomenon of cooperative energy transfer from single Nd 3+, Tm 3+ or Ho 3+ ion simultaneously to the pair of Ce 3+ ions and from single Er 3+ ion to three Ce 3+ ions with, respectively, two and three times smaller transition energy each in highly concentrated La 1− x Ce x F 3 crystals is presented. The influence of overlap integral (between donor ion and cooperative pair and triple Ce 3+ acceptor) and electronic matrix elements of donor transitions on the cooperative energy transfer rate for a set of donor ions is discussed.