Nanoscale Anisotropic Plastic Deformation in Single Crystal Aragonite

The nanoscale anisotropic elastic-plastic behavior of single-crystal aragonite is studied using nanoindentation and tapping mode atomic force microscopy imaging. Force-depth curves coaxial to the $c$ axis exhibited load plateaus indicative of dislocation nucleation events. Plasticity on distinct slip systems was evident in residual topographic impressions where four pileup lobes were present after indentation with a conospherical probe and distinct, protruding slip bands were present after indentation with a Berkovich pyramidal probe. A finite element crystal plasticity model revealed the governing roles of the $\{110\}⟨001⟩$ slip system family, as well as the $(100)[010]$, $(100)[001]$, $(010)[100]$, $(010)[001]$, $(001)[100]$, and $(001)[010]$ systems.