Figure 5.

The effect of the gain on atomic-level LFM images (color range adjusted). (a–c) LFM images of multilayer graphene acquired at various gain values and at a scan rate of 19 Hz. The lattice structure became more difficult to identify, as the gain value increased. All scale bars are calibrated and represent 2 nm; (d) number of pixels by the LFM value for different gains. The vertical axis indicates how many pixels in an image belong to a certain LFM value. As the gain increased, the LFM data values were more spread out from the mean.