Mechanism of barium fluoride with electroplasticity: multiscale insights

• The anisotropic electro-plastic effect of monocrystalline BaF 2 is confirmed. • Electric fields regulate plasticity by controlling dislocation nucleation and slip motion. • The intrinsic mechanism of EF-controlled dislocation motion is revealed by first principle calculation. • A positive correlation between dislocation barrier and field intensity is demonstrated. • The electro-plastic mechanism of BaF 2 is revealed by multiscale experiments and simulations. Electric-assisted manufacturing provides a promising approach to enhance the plasticity of non-conductive materials, but the influence of applied electric fields (EFs) on the mechanical performance and plastic deformation mechanisms of monocrystalline Barium fluoride (BaF 2 ) remain scarce. In this study, molecular dynamics (MD) simulations combined with first-principles (DFT) calculations were employed to elucidate the regulatory role of EF orientation and intensity in governing the plastic response of monocrystalline BaF 2 from a multi-scale perspective. Indentation tests are conducted under varying electric field conditions to identify the effect of the electric field on the plasticity of BaF 2 . The MD simulations indicated that the electro-plastic effect is strongly anisotropic, as distinct EF orientations may either facilitate or hinder dislocation nucleation and slip, thereby modifying hardness and plastic flow behavior. Intensified EFs were found to accelerate dislocation motion and enhance plasticity, whereas particular orientations (e.g., 240EF 2 ¯ 11 ) produced pronounced reverse electro-plastic effects. Furthermore, DFT results confirmed that applied EFs substantially alter the energy barriers for dislocation slip. Specifically, as the field strength increased from 0 to 3 V/nm, the barrier rose from 1.74 eV to 4.60 eV, generating a significant inhibitory effect on dislocation propagation. The systematic study clarifies electro-plasticity in ionic crystals, guiding future electric field-assisted machining techniques.