Knowledge Bank

It is known that ZnH has a relatively shallow potential curve in its ground state ($De\sim 7$, $660cm-1$), however, accurate spectral information on the higher vibrational levels in the $X2\Sigma +$ state is not available. In this study, we recorded Fourier transform spectra in 400-500 nm region using a DC discharge inside a tube furnace. A deep blue emission was observed over the granulated zinc heated to 770 K in a slow flow of Ar ($\sim 5$ Torr) with a trace of $H2$. So far we identified $A2\Pi -X2\Sigma +$ transitions up to $v\prime =2$ and $v\prime \prime =4$, as well as the $B2\Sigma +-X2\Sigma +0-4$ band. In this $B-X$ band, lines are found to be diffuse around $N\prime \prime =21$ and completely dissapear for higher-$N\prime \prime$. Based on the potential curve in the ground state, we found that this happens because of rotational predissociation. We also discuss a deperturbation of the $A2\Pi$ and $B2\Sigma +$ states.