Synthesis and Characterization of the Mg₂SixGe₁₋x Solid Solution

The Mg 2 Si x Ge 1- x solid solution was prepared by heating stoichiometric amounts of elemental Mg, Si, and Ge in an argon atmosphere. Both microprobe and X-ray diffraction analysis of the reaction products suggest that homogeneous alloys can be made by heating the elements to 1200 °C, a temperature roughly 100 °C in excess of the melting temperatures for pure Mg 2 Si and Mg 2 Ge. 29 Si solid-state nuclear magnetic resonance was used to characterize the Mg 2 Si x Ge 1- x solid solution. The 29 Si isotropic chemical shift changes consistent with the band gap in these materials while the line width increases with local disorder.