Tl containing Ar, Kr, and Xe matrices were produced by electrode sputt
ering in a self-igniting pulsed-discharge unit. The absorption and las
er-induced fluorescence spectra of the thallium atoms have been invest
igated. The results are compared with our recent observations of gas p
hase diatomic thallium-rare gas (Tl-Rg) clusters. The observed linewid
ths, shifts, and relaxation dynamics are qualitatively interpreted on
the basis of the pairwise Tl-Rg interaction potentials.