Inversion in conductivity type of GaSb fromp‐ ton‐ has been observed as a result of argon ion beam milling. Electron beam induced current (EBIC) measurements have been employed for detecting the type conversion. Enhancement in the luminescence intensity is seen after ion beam treatment. The type conversion is proposed to occur due to a combined effect of generation of native donors and gettering of native acceptors originally present in the as‐grown samples. ©1995 American Institute of Physics.