67Zn Mössbauer study of zinc metal at high pressure.

A high-pressure M\"ossbauer spectrometer for the high-resolution 93.3-keV resonance in $^{67}\mathrm{Zn}$ was used to investigate Zn metal under pressures up to 5.8 GPa at 4.2 K. Drastic changes of the M\"ossbauer parameters are observed. The recoil-free fraction as well as the center shift change linearly with reduced volume. The former increases by a factor of \ensuremath{\sim}3 at 5.8 GPa, whereas the center shift decreases when pressure is applied. The reduction of the c/a ratio under pressure leads to a decrease of the electric field gradient at the $^{67}\mathrm{Zn}$ nucleus which is partially compensated for by an increase caused by the reduction in volume.