Search

The absorption spectrum of YbCl_3·6H_2O has two sharp lines near 9700 A which are interpreted as the transitions from the M = 5/2 Stark component of the ^2F_7/2 level of the Yb^+++ ion to the M=3/2 and 5/2 levels of the other doublet component ^2F_5/2. The Zeeman splittings of the two lines were investigated at 4°K as a function of the orientation of the crystal. They can be interpreted by assuming that the crystal field has a pronounced magnetic symmetry axis (probably sixfold) perpendicular to the twofold symmetry axis of the crystal. The magnetic ellipsoid is degenerate into a pair of planes perpendicular to this axis. The direction of the magnetic axis is slightly different for the three observed states and bears no relation to the optic axes of the crystal.

More then 2600 new lines have been measured in the emission spectra of H_2 and D_2 between 1.15 and 1.97 µ, with lead sulfide cells and powerful discharge tubes. Most of the strong lines below 1.65 µ belong to known band systems. Beyond this, new and so far incompletely analyzed band systems become prominent.