Fig. 3: Tribological tests between graphite flakes and n-Si.
From: Microscale Schottky superlubric generator with high direct-current density and ultralong life
a Morphological characterization of the two-dimensional single crystal surface of a graphite flake (the colour bar represents height). b Morphological characterization of the n-Si surface. c Frictional force under different normal forces with a displacement amplitude of 2 μm and speed of 4 μm/s, where blue and red points correspond to loading and unloading processes, respectively; each point and error bar were obtained by 40 tests and had friction coefficients of 0.0039 and 0.0045, respectively. d Measured friction force during 6000 continuous sliding cycles with a displacement amplitude of 4 μm and speed of 8 μm/s under a normal force of N = 23.8 μN; the illustration is an optical image of the experimental setup, and the yellow dashed frame is the sliding region. e Morphological characterization of an n-Si interface after 6,000 sliding cycles; the red dashed frame in d is the characterization region. f Raman characterization of the graphite flake interface after 6,000 sliding cycles; points 1–9 represent the test positions.
