Mössbauer Effect of the 93-keV Transition inZn67

Mössbauer spectra obtained with carefully annealed sources consisting of ${\mathrm{Ga}}^{67}$ in ${\mathrm{Zn}}^{66}$O and with ${\mathrm{Zn}}^{67}$O absorbers show a well-resolved hyperfine structure that can be attributed to equal quadrupole splittings in source and absorber, with coupling constants $e^{2}qQ=2.47\mathrm{}\pm 0.03$ MHz. The resonant absorption for the strongest line of the spectrum ranges from about 0.15 to 0.55% and its linewidth from 2.7 to 5 times the natural width $2{\Gamma }_0$. A pressure of about 40 kbar applied to the source gives rise to about an 8% reduction in its quadrupole coupling constant.