Local structure study of GeMn recrystallization process by helium ion beam-induced epitaxial crystallization

•The Mn implanted Ge was suddenly recrystallized into single crystal as the helium dose up to 76dpa.•Helium ion irradiation can be used to regrowth the Mn implanted Ge into single crystalline.•The Ge sponge-like structure induced by implantation can be degraded by helium irradiation.