SPECTROSCOPY AND RELAXATION PATHS OF HIGHER ELECTRONIC STATES OF HG ATOMS AND HG2 MOLECULES IN RARE-GAS MATRICES

Absorption, emission and fluorescence-excitation spectra are reported for Hg atoms and Hg2 molecules in Ar, Kr, Xe and N2 matrices upon excitation by synchrotron radiation in the 260-90 nm range. The fluorescence emitted from all levels issued from the 6s6p configuration (including strongly forbidden P-3(0)-->S-1(0) and P-3(2)-->S-1(0) transitions) upon the excitation of autoionized (5d)9(6s)2(np) levels is explained by ionization-recombination processes. Upon excitation of the P-1(1) level, the efficiency of the P-1(1)-->P-3J relaxation depends strongly on the host properties. Preliminary conclusions concerning environment effects on oscillator strengths, relaxation and ionization-recombination processes are discussed.