Abstract
The M1 admixtures in the 74.6 keV (3
+ → 2
+), 122.8 KeV (5
+ → 4
+) and 146.3keV (6
+ → 5
+) transitions in the γ-vibrational band of
168Er have been determined to be 33 ± 1, 29 ± 2 and 22 ± 6 percent from measurements of L subshell conversion line intensity ratios. It is shown that the M1 admixtures in the intra-band transitions in the
γ-band are a general and suprisingly constant feature in deformed rare-earth nuclei. This suggests that they are the result of a collective effect. The theory of Greiner, which takes the diferent deformation of the proton and nuetron cores into account, is found to be able to give a quantitative explanation of the observed M1 admixtures.