One of the promising approaches to achieving large scale superlubricity is the use of junctions between existing ultra-flat surface together with superlubric graphite mesas. Here we studied the frictional properties of microscale graphite mesa sliding on the diamond-like carbon, a commercially available material with a ultra-flat surface. The interface is composed of a single crystalline graphene and a diamond-like carbon surface with roughness less than 1 nm. Using an integrated approach, which includes Argon plasma irradiation of diamond-like carbon surfaces, X-ray photoelectron spectroscopy analysis and Langmuir adsorption modeling, we found that while the velocity dependence of friction follows a thermally activated sliding mechanism, its temperature dependence is due to the desorption of chemical groups upon heating. These observations indicate that the edges have a significant contribution to the friction. Our results highlight potential factors affecting this type of emerging friction junctions and provide a novel approach for tuning their friction properties through ion irradiation.

中文翻译：

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微米级石墨-DLC异质结构的温度和速度相关摩擦

实现大规模超润滑的一种有前途的方法是在现有的超平坦表面与超润滑石墨台面之间使用接合点。在这里，我们研究了在类金刚石碳上滑动的微型石墨台面的摩擦特性，类金刚石碳是一种具有超平表面的可商购材料。该界面由单晶石墨烯和粗糙度小于1 nm的类金刚石碳表面组成。使用包括金刚石等碳表面的氩等离子体辐照，X射线光电子能谱分析和Langmuir吸附模型在内的集成方法，我们发现，虽然摩擦的速度依赖性遵循热激活滑动机理，但其温度依赖性是由于加热时化学基团的解吸。这些观察结果表明边缘对摩擦有重要影响。我们的研究结果突出显示了影响这种新型摩擦连接的潜在因素，并提供了一种通过离子辐照来调节其摩擦性能的新颖方法。