Nuclear Alignment ofCo58

Abstract

By using a two-stage adiabatic demagnetization technique, ${\mathrm{Co}}^{58}$ nuclei were aligned in single crystals of (22.7% Cu 77.3% Zn) $K_2{\left(\mathrm{S}{\mathrm{O}}_4\right)}_2·6{\mathrm{H}}_2\mathrm{O}$ containing a trace of cobalt. Both the 0.805-Mev and 1.6-Mev gamma rays were measured at three angles as a function of the paramagnetic susceptibility. The 1.6-Mev gamma ray was determined to be quadrupole. A parameter $\lambda$ related to the mixture of Fermi and Gamow-Teller interactions in the allowed beta decay was determined to be 0.11±0.04 in the transition to the 0.805-Mev level in ${\mathrm{Fe}}^{58}$ and 0.45±0.11 in the transition to the 1.6-Mev level. By using the 0.805-Mev counting rate as a thermometer, the paramagnetic susceptibility was determined as a function of the absolute temperature and fitted to the formula $\chi \mathrm{}\left(T\right)=\left(\frac{c}{T}\right)F{\mathrm{}\left(T\right)\mathrm{}}_{\mathrm{hfs}}(1+\frac{\Delta }{T}+\frac{\epsilon }{T^2})$. The data indicate an antiferromagnetic interaction between copper ions, in disagreement with previous work.