Conduction Band Structure of Germanium-Silicon Alloys

Previous measurements of the magnetoresistance and Hall effect in $n$-type germanium-silicon alloy single crystals have been extended to higher silicon compositions. These observations at room temperature show that in alloys with silicon content greater than 23%, the electronic conduction takes place in energy minima which are spheroids oriented along the [100] axes in the reduced zone. It is inferred from these observations that electrons in these minima have about the same effective mass in the alloys (and probably in germanium) as in pure silicon.