Paramagnetic Resonance Hyperfine Structure ofCo60

Abstract

The microwave paramagnetic resonance hyperfine structure of ${\mathrm{Co}}^{60}$ has been observed in a magnetically dilute single crystal of cobalt ammonium sulfate at 20°K. From the number of hfs components and from their spacing relative to those of ${\mathrm{Co}}^{59}$, the spin $I\left({\mathrm{Co}}^{60}\right)=5\mathrm{}$ and the magnetic moment $\left|\mu \right({\mathrm{Co}}^{60}\left)\right|=3.800\mathrm{}\pm 0.007$ nm are directly determined. These results are discussed in relation to those of $\beta$, $\gamma$ spectroscopy, nuclear alignment experiments, and the nuclear shell model.