Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg, South Africa.
1] Nanotechnology and Integrated Bioengineering Center (NIBEC), School of Engineering, University of Ulster, Jordanstown campus, Newtownabbey, BT37 0QB, United Kingdom [2].
Sci Rep. 2014 Jan 24;4:3862. doi: 10.1038/srep03862.
We report an investigation into the magnetic and electronic properties of partially hydrogenated vertically aligned few layers graphene (FLG) synthesized by microwave plasma enhanced chemical vapor deposition. The FLG samples are hydrogenated at different substrate temperatures to alter the degree of hydrogenation and their depth profile. The unique morphology of the structure gives rise to a unique geometry in which graphane/graphone is supported by graphene layers in the bulk, which is very different from other widely studied structures such as one-dimensional nanoribbons. Synchrotron based x-ray absorption fine structure spectroscopy measurements have been used to investigate the electronic structure and the underlying hydrogenation mechanism responsible for the magnetic properties. While ferromagnetic interactions seem to be predominant, the presence of antiferromagnetic interaction was also observed. Free spins available via the conversion of sp(2) to sp(3) hybridized structures, and the possibility of unpaired electrons from defects induced upon hydrogenation are thought to be likely mechanisms for the observed ferromagnetic orders.
我们报告了一项关于部分氢化垂直排列少层石墨烯 (FLG) 的磁性和电子特性的研究，该 FLG 是通过微波等离子体增强化学气相沉积合成的。FLG 样品在不同的衬底温度下进行氢化，以改变氢化程度和深度分布。该结构的独特形态导致了一种独特的几何形状，其中在体相中，石墨烷/石墨酮由石墨烯层支撑，这与其他广泛研究的结构（如一维纳米带）非常不同。基于同步加速器的 X 射线吸收精细结构光谱测量已被用于研究电子结构和导致磁性的基础氢化机制。虽然铁磁相互作用似乎占主导地位，但也观察到反铁磁相互作用的存在。通过将 sp(2) 转化为 sp(3) 杂化结构可获得自由自旋，并且氢化过程中诱导的缺陷可能存在未配对电子，这被认为是观察到的铁磁有序的可能机制。
