Electric-field-gradient tensor for cadmium impurities inα-gallium

The electric field gradient in orthorhombic gallium metal at the site of a ${}_{}{}^{111}{}_{}{}^{}\mathrm{Cd}$ probe atom was investigated by means of the time-differential perturbed angular correlation method. By a measurement of the quadrupolar interaction in a polycrystalline sample, the quadrupole coupling constant (at 293 K) $e^2$Qq/h=139.4(17) MHz and the asymmetry parameter η=0.215(5) were determined. Single-crystal experiments with and without external magnetic field yielded the orientation of the electric-field-gradient tensor principal-axis system in the crystal lattice.