| Abstract Scope |
Classical phase diagrams describe stability using temperature and composition, implicitly assuming near-equilibrium conditions. In current-carrying materials, sustained electric current drives structural evolution that cannot be explained by Joule heating alone. Here, we present a cross-system synthesis showing that electronic perturbation acts as an independent driving field, requiring an extension of phase-diagram thinking. Using electric-current stressing experiments combined with synchrotron X-ray diffraction, EBSD, and TEM, we examine Cu–Sn-based intermetallics and oxide-free Au conductors. Across these systems, we observe reversible lattice expansion during current stressing followed by irreversible lattice contraction upon quenching, accompanied by current-dependent grain reorientation and defect redistribution. The persistence of post-current contraction in Au excludes oxidation-based mechanisms and points to electron-wind-driven stress relaxation as a unifying origin. Based on these observations, we propose a current–temperature (J–T) stability map delineating regimes of reversible deformation and irreversible structural reorganization under electronic driving. |