Photoassociation and bound-bound excitation into the 22Π state of LiZn, LiCd, and NaZn molecules

The photoassociation and bound-bound excitation processes of alkali-metal–group-IIB molecules have been studied for the LiZn, LiCd, and NaZn molecules. We considered two main factors relevant to these processes, namely, the densities of collision complexes and the relevant absorption coefficients. Densities in the vapor mixture were manipulated by preparation of different metal alloys, whereas the free-bound or bound-bound absorption is selected by changing a laser wavelength used for the excitation. The 2${\mathrm{}}^2$Π states were directly excited by the laser wavelength in the spectral range 435–450 nm. The densities of the LiZn, LiCd, and NaZn excimers were estimated from alkali-metal and Zn (Cd) densities using the dissociation equilibrium equation for the corresponding excimers in the ground state. The experimentally observed LiZn excimer band at 477 nm was satisfactory compared with the appropriate theoretical simulation, assuming free-bound excitation of the 2${\mathrm{}}^2$Π state at 438.5 nm. © 1996 The American Physical Society.