We examined the epitaxial growth of Ge1−x
Sn
x
thin film with x~0.50 on GaSb(111) substrate using a low-temperature molecular beam epitaxy. X-ray diffraction and Raman scattering spectroscopy analyses revealed that the Ge1−x
Sn
x
thin film with x~0.50 with no strain was successfully grown on GaSb(111). Furthermore, in the Raman analysis, Ge1−x
Sn
x
with x~0.50 showed a sharper Ge-Sn peak compared to Ge-Ge and Sn-Sn peaks, and an improved thermal stability than Ge1−x
Sn
x
with a smaller Sn composition. This suggests that the Ge1−x
Sn
x
with x~0.50 would have an ordered Ge-Sn bonding like a zinc blend system, that is significantly different from Si1−x
Ge
x
case.