The emission spectrum of bismuth monofluoride BiF—‘A’ system

Summary

The observation of (A-X) system of BiF has been extended up to λ 5316 and twenty new bands belonging to this system have been recorded. The band heads could be represented by the following equation:

$$v = 22959 \cdot 9 + 381 \cdot 0(v' + \tfrac{1}{2}) - 3 \cdot 0(v' + \tfrac{1}{2})^2 + 0 \cdot 1(v' + \tfrac{1}{2})^3 - 512 \cdot 0(v'' + \tfrac{1}{2}) + 2 \cdot 1$$

Seven other faint bands in the region λ 5316-5492 have also been reported, which, however, could not be classified. By our analysis of the present data and from known thermochemical data it has been deduced that the ground state dissociation energy is, in all probability, around 20000 cm.⁻¹ (∼2·5 ev.) and that the dissociation products are the normal Bi and F atoms. The dissociation energy of the upper state and the correlation rules have been used to show that the dissociation products in the upper state are very likely to be Bi atom in the excited state²D_3/2 and F atom in its ground state (²P_3/2).