Knowledge Bank

The electronic spectroscopy of the yttrium monosulfide molecule (YS) has been studied in the pulsed supersonic jet apparatus. The molecules were produced by chemical reaction in a laser-generated plasma. Laser induced fluorescence spectra were recorded in the region 600-800 mm using a pulsed dye laser ($0.006cm-1$ bandwidth). In addition to the previously reported $A2\Pi -X2\Sigma +$ and $B2\Sigma +-X2\Sigma +$ systems, some new transitions were observed. Several bands were probed at a resolution of 120 MHz using a single mode ring dye laser to excite flourescence. Perturbations in the $B2\Sigma +-X2\Sigma +$ (0,0) band were observed and will be discussed. Stark spectroscopy was performed on the first lines of the $Pc$ and $Re$ branches of the $B2\Sigma +-X2\Sigma -$ (0,0) band in order to determine the dipole moments of the X and B states respectively. Results are compared with recent work on related group III transition metal molecules.