Spectroscopy of mass-selected gadolinium dimers in argon matrices

We report on the absorption, resonance Raman, and Raman excitation profile spectra of mass-selected gadolinium dimers in argon matrices. Two dimer abs orption bands were found between 570 and 660 nm. The Raman excitation profi le resembles the dimer absorption spectrum very well. Resonance Raman spect ra, obtained by excitation into this region with dye laser radiation, give a single progression with up to four Stokes transitions. These data give om ega(e)=138.7 +/- 0.4 cm(-1) with omega(e)x(e)=0.3 +/- 0.1 cm(-1), leading t o a spectroscopic dissociation energy of 2.1 +/- 0.7 eV. (C) 2000 American Institute of Physics. [S0021-9606(00)00222-1].