Ductile binary FCC materials screened by anisotropic and isotropic elastic criteria: first principle insights into deformation mechanisms.

Unlike two-dimensional van der Waals (2D vdW) materials, which achieve deformability through dimensional reduction, bulk materials rely more on their intrinsic crystal structures and chemical bond interactions for ductility. Considering the multi-scale complexity of plastic deformation and failure in bulk materials, we propose using B/G and κ criteria to synergistically pre-screen ductile materials. From 152 binary face-centered cubic (FCC) materials, we screened 16 compounds with good ductility, including zincblende structured FeN and rocksalt structured CdO. First principle calculations show that uniform deformation of the atomic framework is the main deformation mechanism for FeN and CdO. Both materials exhibit significant strain before failure, demonstrating good deformability. Shear-induced perfect dislocation slip of (111)/[Formula: see text] in the shuffle-set plane leads to the restoration and stress release of the FeN structure, thereby conferring potential ductility. For CdO, its two slip systems with lower ideal shear strengths are prone to simultaneous activation, and the < 001> direction exhibits a large tensile strain together with a low ideal tensile strength, both of which may promote its ductility. Generalized stacking fault energy (GSFE) calculations confirm the lowest energy barriers for the most active slip systems, consistent with the ideal shear strength results. This work provides a combined elastic criteria screening strategy and mechanistic insights into ductile binary FCC materials.