Departamento de Física de la Materia Condensada and Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain.
J Phys Condens Matter. 2011 Sep 7;23(35):355008. doi: 10.1088/0953-8984/23/35/355008. Epub 2011 Aug 16.
We present a theoretical study of the effect of surface defects on atomic friction in the stick-slip dynamical regime of a minimalistic model. We focus on how the presence of defects and temperature change the average properties of the system. We have identified two main mechanisms which modify the mean friction force of the system when defects are considered. As expected, defects change the potential profile locally and thus affect the friction force. But the presence of defects also changes the probability distribution function of the tip slip length and thus the mean friction force. We corroborated both effects for different values of temperature, external load, dragging velocity and damping. We also show a comparison of the effects of surface defects and surface disorder on the dynamics of the system.
我们对表面缺陷对微尺度模型粘着-滑动态中原子摩擦力的影响进行了理论研究。我们关注缺陷和温度如何改变系统的平均性质。我们已经确定了两种主要机制，当考虑缺陷时，这两种机制会改变系统的平均摩擦力。正如预期的那样，缺陷会局部改变势场，从而影响摩擦力。但是缺陷的存在也会改变尖端滑动长度的概率分布函数，从而改变平均摩擦力。我们在不同的温度、外载荷、拖动速度和阻尼下验证了这两种效应。我们还比较了表面缺陷和表面无序对系统动力学的影响。
