fig2

Figure 2. Elastic property characterizations. (A) Nanoindentation Load–displacement curves measured on the (001) plane of CIPS-IPS crystal. The blue arrows indicate pop-ins due to fracture damage. (B) The contact resonant frequency image measured by CR-AFM. (C) The friction force image measured by LFM. (D) The phase image measured by PFM. (B-D) and Figure 1D are in the same region. (E) The resonance frequencies of the cantilever from free resonance to contact resonance on HOPG and CIPS-IPS. (F and G) CR-AFM mapping of the first-order contact resonance frequency in HOPG and CIPS-IPS, respectively. Inset: Frequency histogram and Gauss fitting curves. (H) The relationship between the normalized contact stiffness k^*/k_lever and the relative tip position γ.