Tuček Jiří, Holá Kateřina, Zoppellaro Giorgio, Błoński Piotr, Langer Rostislav, Medved' Miroslav, Susi Toma, Otyepka Michal, Zbořil Radek
Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacký University in Olomouc , Šlechtitelů 27 , 783 71 Olomouc , Czech Republic.
Faculty of Physics , University of Vienna , Boltzmanngasse 5 , 1090 Vienna , Austria.
ACS Nano. 2018 Dec 26;12(12):12847-12859. doi: 10.1021/acsnano.8b08052. Epub 2018 Dec 10.
Stabilization of ferromagnetic ordering in graphene-based systems up to room temperature remains an important challenge owing to the huge scope for applications in electronics, spintronics, biomedicine, and separation technologies. To date, several strategies have been proposed, including edge engineering, introduction of defects and dopants, and covalent functionalization. However, these techniques are usually hampered by limited temperature sustainability of ferromagnetic ordering. Here, we describe a method for the well-controlled sp functionalization of graphene to synthesize zigzag conjugated sp carbon chains that can act as communication pathways among radical motifs. Zigzag sp/sp patterns in the basal plane were clearly observed by high-resolution scanning transmission electron microscopy and provided a suitable matrix for stabilization of ferromagnetic ordering up to room temperature due to combined contributions of itinerant π-electrons and superexchange interactions. The results highlight the principal role of sp/sp ratio and superorganization of radical motifs in graphene for generating room-temperature nonmetallic magnets.
在基于石墨烯的系统中，将铁磁有序稳定至室温仍然是一项重大挑战，因为其在电子学、自旋电子学、生物医学和分离技术等领域具有巨大的应用潜力。迄今为止，已经提出了几种策略，包括边缘工程、引入缺陷和掺杂剂以及共价功能化。然而，这些技术通常受到铁磁有序有限的温度可持续性的阻碍。在此，我们描述了一种对石墨烯进行精确控制的sp功能化方法，以合成锯齿形共轭sp碳链，这些碳链可作为自由基基序之间的通信途径。通过高分辨率扫描透射电子显微镜清楚地观察到了基面中的锯齿形sp/sp模式，由于巡游π电子和超交换相互作用共同作用，该模式为将铁磁有序稳定至室温提供了合适的基质。这些结果突出了石墨烯中sp/sp比率和自由基基序的超组织在生成室温非金属磁体方面的主要作用。
