Doping effect on electrical transport properties in the semimetallic compound LiAl

The temperature-dependent Hall coefficient and electrical resistivity above 77 K of Ga- and In-doped LiAl are presented. "Positive" Hall coefficients were observed in doped LiAl as well as for pure LiAl. Following Zunger, we propose that the conduction-band\char22{}valence-band overlap varies as the lattice parameter. The conduction mechanisms are discussed in terms of one- and two-carrier models, respectively, for Ga-doped LiAl and In-doped LiAl.