SPECTRA AND RELAXATION PATHS OF HG(3P1) IN RARE-GAS MATRICES

Absorption, fluorescence-excitation and fluorescence spectra, and lifetimes have been measured for P-3(1) <-- --> S-1(0) and P-3(0) --> S-1(0) transitions in Hg atoms isolated in Ar, Kr, and Xe matrices. In all systems, the P-3(1) state decays mainly by fluorescence emission; the P-3(1) --> P-3(0) relaxation, inducing the long-lived P-3(0) --> S-1(0) emission, being very inefficient. The P-3(1) --> S-1(0) emission in Ar and Kr is a mirror image of the absorption, while a strong redshift in Xe corresponds to the formation of Hg*Xe exciplexes. The results are discussed in a model assuming the additivity of interatomic potentials deduced from the spectroscopic studies of jet-cooled Hg-rare-gas complexes.