Post-growth purification of Co nanostructures prepared by focused electron beam induced deposition

作者：Begun E^*; Dobrovolskiy O V; Kompaniiets M; Sachser R; Gspan Ch; Plank H; Huth M

来源：Nanotechnology, 2015, 26(7): 075301.

DOI：10.1088/0957-4484/26/7/075301

• focused electron beam induced deposition
• cobalt
• post-growth purification
• magneto-transport

In the majority of cases nanostructures prepared by focused electron beam induced deposition (FEBID) employing an organometallic precursor contain predominantly carbon-based ligand dissociation products. This is unfortunate with regard to using this high-resolution direct-write approach for the preparation of nanostructures for various fields, such as mesoscopic physics, micromagnetism, electronic correlations, spin-dependent transport and numerous applications. Here we present an in situ cleaning approach to obtain pure Co-FEBID nanostructures. The purification procedure lies in the exposure of heated samples to a H-2 atmosphere in conjunction with the irradiation by low-energy electrons. The key finding is that the combination of annealing at 300 degrees C, H-2 exposure and electron irradiation leads to compact, carbon-and oxygen free Co layers down to a thickness of about 20 nm starting from as-deposited Co-FEBID structures. In addition to this, in temperature-dependent electrical resistance measurements on post-processed samples we find a typical metallic behavior. In low-temperature magnetoresistance and Hall effect measurements we observe ferromagnetic behavior.

• 出版日期2015-2-20