Figure 1
From: Large Electric Field–Enhanced–Hardness Effect in a SiO2 Film
Force–curve and secant slope of the loading part at 0 V tip bias.
(a) Loading–unloading curve for SiO2 with a tip bias of 0 V. (b) Secant slope of the loading curve in Fig. 1a from the zero deflection signal point (zero load signal) to the subsequent deflection signal.
