论文标题
石墨烯片上碳纳米颗粒的摩擦和活动性
Friction and mobility of carbon nanoparticles on a graphene sheet
论文作者
论文摘要
使用分子动力学的方法表明，碳纳米颗粒（矩形石墨烯薄片，尺寸$ l <10 $ nm的球形富勒烯）的运动可以描述为平坦基板上的热烯石化烯片的表面，可以描述为粒子在具有液体数值的恒定系数中的粒子运动中的运动量和粒径的恒定数值，并依赖于温度的粒子。已经显示出有两种有效摩擦：扩散和弹道。在运动状态（在速度$ v> 100 $ m/s的情况下），由于移动纳米颗粒与石墨烯片的平面外弯曲振动的相互作用而发生减速。因此，随着温度的升高，摩擦系数单调增加。在运动的扩散状态（$ V <10 $ m/s）中，由于粒子需要克服局部能屏障而产生摩擦，因此随着皇帝的增加而减少。在低温下，弹道和扩散摩擦之间的差异最为明显，因为弹道运动状态中纳米颗粒的迁移率随温度的升高而降低，而在扩散状态下，它单调增加。结果表明，将纳米颗粒压到底物的正常力的存在导致其与底物的摩擦增加。
It is shown using the method of molecular dynamics that the motion of carbon nanoparticles (rectangular graphene flakes, spherical fullerenes of size $L<10$ nm) on the surface of a thermalized graphene sheet lying on a flat substrate can be described as the motion of particles in a viscous medium with a constant coefficient of friction, the value of which depends on the temperature and particle size. It has been shown that there are two types of effective friction: diffusion and ballistic. In ballistic regime of motion (at velocities $v>100$ m/s), deceleration occurs due to the interaction of moving nanoparticles with thermal out-of-plane bending vibrations of a graphene sheet. Because of this, with the increasing temperature, the coefficient of friction monotonically increases. In the diffusion regime of motion (at $v<10$ m/s), friction arises due to the need for the particle to overcome local energy barriers, therefore it decreases with increasing emperature. The difference between ballistic and diffusion friction is most pronounced at low temperatures, since the mobility of nanoparticles in the ballistic regime of motion decreases with increasing temperature, while in the diffusion regime it monotonously increases. It is shown that the presence of a normal force pressing the nanoparticle to the substrate leads to an increases in its friction with the substrate.
