125Te-Moebauer study of tellurium at high pressure

The effects of pressure on the hyperfine interaction parameters of 125Te in Te have been studied at pressures up to about 110 kbar using the 35.5-keV Moesbauer transition of 125Te. The isomer shift increases while the electric-quadrupole interaction decreases with increasing pressure. The slopes of the pressure dependencies of both parameters change discontinuously at a pressure of about 50 kbar, corresponding to the pressure-induced semiconductor-metal transition of the Te. The results are interpreted in terms of the chemical bonding in Te. The quadrupole-split Moesbauer spectra observed for the metallic high-pressure phase of the Te reveal a non-cubic lattice structure. (orig.)