Solid State and Nuclear Results from a Mössbauer-Type Study ofAu197

Through the measurement of the hfs of dilute alloys of gold with iron, cobalt, and nickel, the magnetic moment of the first excited state of ${\mathrm{Au}}^{197}$ has been measured as +0.38±0.08 nm. It was found that the hfs coupling constant in the alloys is closely proportional to the magnetic moment of the host ferromagnetic metal. The value of the effective hyperfine field for the iron alloy is $H^{\prime }=(1.46\mathrm{}\pm 0.16)\times {10}^6$ gauss. A study of the isomer shift of the gold-nickel alloy system as its relates to ferromagnetism is presented. The recoilless absorption linewidth as a function of absorber thickness for metallic gold is given. The half-life of the first excited state of ${\mathrm{Au}}^{197}$ is found to be $T_{\frac{1}{2}}=(1.93\mathrm{}\pm 0.2)\times {10}^{-9\mathrm{}}$ sec.