THE ELECTRONIC SPECTRA OF HYDRIDES OF GROUP IIIA METALS

Author Institution: Laboratoire de Spectrom\'{e}trie Ionique et Mol\'{e}culaireUsing a composite wall hollow cathode lamp we were able to excite easily the electronic spectra of group IIIa metal hydrides. Three new electronic band systems of LaH and LaD appearing between 5300 and 6500 {\AA} have been studied. The rotational structure, the intensity distribution in the P, Q, and R branches, and the A-doubling show that these bands may be ascribed to ($^{3}\Phi$ $\rightarrow^{3}\Delta$), ($^{1}\Delta$, $^{1}\Sigma \rightarrow ^{1}\Pi$) transitions. The rotational study of YD and YH has been undertaken