Nanotechnology. 2013 Nov 29;24(47):475708. doi: 10.1088/0957-4484/24/47/475708.
Epitaxial growth of electrodes and tunnel barriers on graphene is one of the main technological bottlenecks for graphene spintronics. In this paper, we demonstrate that MgO(111) epitaxial tunnel barriers, one of the prime candidates for spintronic application, can be grown by molecular beam epitaxy on epitaxial graphene on SiC(0001). Ferromagnetic metals (Fe, Co, Fe20Ni80) were epitaxially grown on top of the MgO barrier, thus leading to monocrystalline electrodes on graphene. Structural and magnetic characterizations were performed on these ferromagnetic metals after annealing and dewetting: they form clusters with a 100 nm typical lateral width, which are mostly magnetic monodomains in the case of Fe. This epitaxial stack opens the way to graphene spintronic devices taking benefits from a coherent tunnelling current through the epitaxial MgO/graphene stack.
在石墨烯上外延生长电极和隧道势垒是石墨烯自旋电子学的主要技术瓶颈之一。在本文中，我们证明了 MgO(111)外延隧道势垒（自旋电子学应用的主要候选材料之一）可以通过分子束外延在 SiC(0001)上外延生长的石墨烯上生长。铁磁金属（Fe、Co、Fe20Ni80）外延生长在 MgO 势垒之上，从而在石墨烯上形成单晶电极。对退火和去湿后的这些铁磁金属进行了结构和磁性表征：它们形成了具有 100nm 典型横向宽度的团簇，在 Fe 的情况下，这些团簇大多是磁性单畴。这种外延堆叠为利用通过外延 MgO/石墨烯堆叠的相干隧穿电流的石墨烯自旋电子器件开辟了道路。
