| 학회 | 한국재료학회 |
| 학술대회 | 2006년 봄 (05/19 ~ 05/20, 경상대학교 ) |
| 권호 | 12권 1호 |
| 발표분야 | 나노 및 생체재료 |
| 제목 | Effect of Be flux on properties of Be codoped GaMnAs |
| 초록 | Improving hole concentration is one of the methods to improve Curie temperature (Tc) of GaMnAs. Be, as expected to be a more effective acceptor than Mn to pursue high hole concentration, has been studied in our previous work, and room temperature magnetization has been obtained via the separation of precipitation. To study the effect of Be flux on the properties of GaMnAs:Be, we grew GaMnAs:Be samples via molecular beam epitaxy (MBE) with varied Mn flux from TMn=870℃ to TMn=950℃ at three Be flux: TBe=1125℃, 1150℃, and 1175℃. Here we report the results of DC-XRD, Hall measurement and superconducting quantum interference device (SQUID). It is well known, during growth process, Be atoms and Mn atoms tend to occupy Ga sites in lattice. However, at a fixed Mn flux, when Be flux reaches a high value, the competition of Be atoms and Mn atoms at Ga sites is inevitable. Since Be is more effective than Mn, most of Be atoms occupy Ga sites. As a result, most Mn atoms are put out from Ga sites and form MnAs precipitation. The quantity of precipitation increases with the increasing of Be flux. Considering Tc of MnAs is about 310 K, room temperature magnetization of our samples is enhanced by increasing Be flux. Simultaneously, the conductivity of film also increases with increasing of Be flux. At low Mn flux, high flux Be codoping also induces the reduction of lattice constant due to the small radius of Be atom. However, this reduction is compensated by large radius Mn atoms at high Mn flux. This work was supported by ReCAMM |
| 저자 | Fucheng Yu1, Cunxu Gao1, Dojin Kim1, Chang-Soo Kim2 |
| 소속 | 1Department of materials science and engineering Chungnam National Univ., 2Korean Research Institute of Standard and Science |
| 키워드 | Be codoped GaMnAs; DMS; MBE |
