Tuning between mixing and reactivity in the Ge-Sn system using pressure and temperature.

No bulk GeSn crystal existed prior to this work. Near 10 GPa the two elements resemble each other both electronically and structurally. Synthesis experiments at 10 GPa and 1500 K followed by annealing at 770 K using Ge and Sn starting materials and ex-situ analysis using transmission electron microscopy, scanning electron microscopy, and X-ray diffraction document the recovery of a Ge(0.9)Sn(0.1) solid solution (space group P4(3)2(1)2, a = 6.014 (1) A, c = 7.057 (1) A, Z = 12).