An investigation into the changes in the electronic structure of polycrystalline and single-crystal copper induced by deformation

Abstract

X-ray diffraction analysis was conducted to investigate changes in the electronic structure of copper samples: polycrystalline M1-grade copper subjected to equal-channel angular pressing (ECAP) and annealing at 200 °C; single-crystal copper deformed by 10% in the (311) plane. X-ray diffraction of the polycrystalline samples revealed dominant (200) and (220) peaks in the initial M1 state. Following ECAP, reflection intensities redistributed, with the (111) peak intensity significantly increasing. Deformation of the single-crystal (311) samples induced a rotation-shear deformation mechanism in the near-surface layer (∼50–100 μm), reorienting the material to the (111) plane and causing electrons in the plane of applied force to transition to lower binding energy levels. While lattice rearrangement was absent in the lateral (220) plane, diffraction peak shifts indicated increasing stress. The electronic spectrum exhibited an increased intensity of higher-energy peaks compared to the plane of applied force, suggesting electron transitions to higher binding energy levels.