Atomic-scale stick–slip friction of monolayer graphene on a copper substrate is computationally studied at a wide range of temperatures, which reveals strong temperature dependence of friction force and friction mode. The increase in temperature distorts regular stick–slip behavior and causes a nonlinear decrease of friction force, demonstrating a friction behavior transition from athermal friction to thermally activated. By analyzing atomic morphologies, the true contact area, defining the number of atoms interacting across the interface, shows a weak temperature dependence, yet the quality of interfacial contact substantially varies with temperature. Spatial distributions of atomic friction force uncover the significant effect of Moiré superlattices, that act as strong pinning sites at low temperatures, partly change to pushing due to nonconcurrent atomic jumps at high temperatures, which leads to a chaotic friction mode with reduced lateral force. Additionally, we demonstrate the role of superlattices in strengthening friction and dictating the periodic stick–slip motion of interfacial sliding.

在较宽的温度范围内，通过计算研究了单层石墨烯在铜基板上的原子尺度粘滑摩擦，这显示了摩擦力和摩擦模式对温度的强烈依赖性。温度的升高会扭曲正常的粘滑行为，并导致摩擦力的非线性下降，这表明摩擦行为从无热摩擦转变为热激活。通过分析原子形态，确定接触界面上相互作用的原子数的真实接触面积显示出较弱的温度依赖性，但界面接触的质量却随温度而显着变化。原子摩擦力的空间分布揭示了莫尔超晶格的显著作用，它在低温下充当强钉扎点，由于在高温下非并发原子跳跃，部分改变为推动，这导致横向摩擦力减小的混沌摩擦模式。此外，我们证明了超晶格在增强摩擦力和指示界面滑动的周期性粘滑运动中的作用。