The effect of Co ion implantation on Ge_(1_x)Mn_x films

摘要

Ge_(1-x)Mn_x (x=0,0.013,0.0226,0.0339,0.0565,0.0678,0.0904,0.113) films prepared by magnetron sputtering at 773 K had a Ge cubic structure except for x=0.1130. Co ion implantation into these films can effectively prevent the formation of a second phase. Both single-doped and co-doped samples were ferromagnetic at room temperature. The d-d exchange interaction between the interstitial Mn (MnT) and the substituted Mn (Mn_(Ge)) resulted in ferromagnetism in the sputtered films. Since Co ion implantation destroyed the Mn_T-Mn_(Ge)-Mn_T complex, the saturated magnetization decreased. Hall measurements revealed that the Co ion implanted films were n-type semiconductors, and the anomalous Hall Effect (AHE) suggested the ferromagnetism was carrier-mediated in the implanted films.