Mn-doping effects on structural and magnetic properties of Ge nanocrystals on insulator

Microstructure and Ferromagnetism of Mn0.05Ge0.95 Quantum Dots/Graphene Heterostructures for Spintronic Devices

“…Early fundamental works were focused on MnGe thin film structures. − Park et al discovered that the Curie temperature ( T C ) increased linearly with the Mn content from 25 to 116 K . However, due to low Mn solubility in Ge, the intermetallic precipitates of Mn and Ge were found in these films, which made the ferromagnetism properties of Mn x Ge 1– x thin films uncontrollable. , Many efforts have been made in the field of Mn x Ge 1– x QDs to obtain stable and controllable ferromagnetism and a high T C . , The quantum confinement effect from Mn x Ge 1– x QDs could enhance the exchange coupling between holes and localized manganese dopants, which in turn enhances the ferromagnetic ordering. − Wang et al obtained Mn x Ge 1– x QDs with a Curie temperature of up to 400 K by molecular beam epitaxy (MBE), which provided the basis for spintronic devices operating normally at room temperature .…”