We synthesized Mo_xW_1−xS₂ alloy by chemical vapor deposition. Raman characterization results showed that the sample is a monolayer with a special structure which transforms from MoS₂ to WS₂. Atomic force microscopy measurements suggested that the friction force decreases from MoS₂ region to WS₂ region. Molecular dynamics simulations verified that interfacial interaction is the determining factor resulting in the variation in the friction properties of monolayer Mo_xW_1−xS₂. Green’s function calculations demonstrated that phonons are excited at both washboard frequency and its harmonics. Besides, the number and total energy of the excited phonons were calculated. The decreasing of the number and total energy of the excited phonons with the weakening interfacial interaction, leading to the decreasing dissipated energy and reduced friction force.

我们通过化学气相沉积合成了 Mo _x W _1-x S ₂合金。拉曼表征结果表明，样品是一个具有特殊结构的单层，从MoS ₂转变为WS ₂。原子力显微镜测量表明摩擦力从MoS ₂区域到WS ₂区域减小。分子动力学模拟证实，界面相互作用是导致单层 Mo _x W _1−x S ₂摩擦性能变化的决定性因素. 格林函数计算表明，声子在搓衣板频率及其谐波处均被激发。此外，计算了激发声子的数量和总能量。随着界面相互作用的减弱，激发声子的数量和总能量减少，导致耗散能量减少，摩擦力减小。