Band Systems of Zirconium Oxide (ZrO) in the Ultra-Violet

Abstract

THREE new systems of ZrO have been observed in the ultra-violet, in addition to the three triplet systems in the visible region analysed by Miss Lowater¹. Lowater also observed twelve bands, degrading to the longer wave-length, in the region 3726–3470 A., differing in general appearance from the triplet systems in the visible, the bands being much weaker and the triplets not easily recognizable. Although thirty-one bands have been measured in the ultra-violet by us, only five of the twelve band-heads measured by Lowater agree with ours. As the atomic spectrum of zirconium in this region is particularly strong, and as the lines are numerous, weak lines have apparently been mistaken for band-heads. However, it has been possible to photograph the ZrO spectrum in the region 2930–6700 A. remarkably free from lines, and to identify the real band-heads. Altogether thirty-one bands were measured in the region 4000–2930 A., and assigned to one singlet and two triplet systems.