Evolution of the Burgers-vector population of Cu-Nb multilayers with 7Â at% He-implantation determined by X-ray diffraction

Extreme environmental conditions have received considerable attention in the last decade in relation to extending lifetime of materials or developing novel capabilities to achieve a higher endurance. Extreme mechanical properties or the extremely high resistance to irradiation are in the limelight. In the present paper, the He implantation-induced lattice-defect structure of Cu/Nb multilayers with different nominal layer widths is investigated based on the evolution of the prevailing Burgers-vector population, the corresponding dislocation density and a varying coherency length. The virgin and the implanted state can be characterized by using individual dislocation contrast factors in the two different phases. After He implantation, the prevailing microstructure displays a majority of out-of-plane, screw-type dislocations in the developed lattice-defect structure.