Post-growth purification of Co nanostructures prepared by focused electron beam induced deposition
Post-growth purification of Co nanostructures prepared by focused electron beam induced deposition
复制标题
DOI：
10.1088/0957-4484/26/7/075301
复制
发表时间：
2015-02-20
期刊：
影响因子：
3.5
通讯作者：
Huth, M.
中科院分区：
文献类型：
--
作者：
Begun, E.;Dobrovolskiy, O. V.;Huth, M.
在大多数情况下，通过使用有机金属前体的聚焦电子束诱导沉积（FEBID）制备的纳米结构主要包含碳基配体解离产物。对于使用这种高分辨率直写方法来制备用于各种领域（例如介观物理、微磁学、电子关联、自旋相关输运和众多应用）的纳米结构来说，这是不幸的。在这里，我们提出了一种原位清洁方法来获得纯 Co-FEBID 纳米结构。纯化过程是将加热的样品暴露在 H-2 气氛中并结合低能电子的照射。主要发现是，300 摄氏度退火、H-2 暴露和电子辐照相结合，可以从沉积的 Co-FEBID 结构开始形成致密、无碳和无氧的 Co 层，厚度降至约 20 nm。除此之外，在对后处理样品进行与温度相关的电阻测量时，我们发现了典型的金属行为。在低温磁阻和霍尔效应测量中，我们观察到铁磁行为。
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.