Quadrupole interactions in graphite–hafnium chloride

The intercalation of graphite by hafnium chloride has been investigated by time-differential perturbed angular-correlation measurements of the (133–482)-keV γ-γ cascade in ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$. Electric-quadrupole interaction parameters were determined for samples prepared both by the two-zone vapor-transport technique and from solution in ${\mathrm{SOCl}}_2$. In the former case the presence of chlorine is shown to be necessary for intercalation to take place and the data are fitted with the combination of a static electric-quadrupole plus time-dependent interaction. When solvent is used for the preparation a more complex spectrum is obtained, requiring an additional static interaction to obtain a reasonable fit.