Effect of a magnetic field on the luminescent lifetime of Cu+ in alkali halide host crystals

We have measured the change in the triplet emission lifetime of the Cu+ impurity in various alkali halide hosts at 4.2 K as a function of applied magnetic field. Pedrini [Phys. Status Solidi B 87, 273 (1978)] has proposed that the Eg3 emitting state is split into T1g and T2g spin-orbit components and has found that the emission lifetime depends sensitively on the splitting. We have utilized an external magnetic field to mix these spin-orbit levels. This produced a measurable decrease in the emission lifetime which we explained with Pedrini's model. We also diagonalized the d9s excited-state matrix to calculate independently the T1g,T2g spin-orbit splitting and obtained reasonable agreement with our experimental results.