Double domes of mesoscopic localized anisotropic lattice strain in HCP-Ag₇₅Al₂₅ under high pressure

In this research, we report a new discovery of anomalous localized anisotropic lattice strain under uniaxial non-hydrostatic pressure to 40 GPa studied with micro-focused synchrotron X-ray diffraction. With experiments on our synthesized nanocrystalline granular material, a phase-stable HCP-Ag₇₅Al₂₅ alloy, the analyzed results show direct evidence that reaching a critical value of localized anisotropy in the lattice strain leads to grain fracture. This discovery of the evolution in such anomalous anisotropic strain further reveals the link between micro- and macroscopic anisotropic mechanical behaviors of granular materials through a mesoscopic way and may set a reference for further studies on materials anisotropy or designing new materials with specific anisotropic mechanical properties.