Hyperfine fields at Ga 66, Ge 67,69 implanted into iron and gadolinium hosts at 6 K, and applications to g -factor measurements HYPERFINE FIELDS at Ga 66, Ge 67,69 ... T. J. GRAY et al.

Isomers in Ga66, Ge67, and Ge69 were recoil implanted into ferromagnetic hosts of iron and gadolinium at ≈6 K, and the hyperfine magnetic fields were determined by time differential perturbed angular distribution (TDPAD) measurements. The hyperfine field strengths at ≈6 K are compared to the results of previous higher-temperature measurements and the amplitudes of the R(t) functions are compared to empirical expectations. The results show that gadolinium can be a suitable host for high-precision in-beam g-factor measurements. The results of new g-factor measurements for isomers in Ga66 and Ge67 are g(Ga66, 7-)=+0.126(4), supporting a [πf5/2a - νg9/2]7- configuration assignment, and g(Ge67, 9/2+)=-0.1932(22), derived from a new measurement of the ratio g(67Ge)/g(69Ge)=0.869(9). These values are in agreement with previous results. The R(t) amplitudes indicate that the nuclear alignment produced in the isomeric states was significantly lower than the empirically expected σ/I≈0.35.