fig4

Figure 4. Distributions of vacancies, dislocations, stacking faults, and twin boundaries in equal-sized NPs for (A-C) 20 nm Ag NPs sintered at 60%T_m at the beginning, intermediate, and final stages of sintering; (D and E) 15 nm Cu NPs sintered at 60%T_m and 70%T_m at the final stage; (F and G) 25 nm Cu NPs sintered at 60%T_m at the beginning and final stages of sintering. Black arrows mark dislocations, stacking faults, and twin boundaries, while light blue arrows point to vacancies. See Supplementary Materials for animations of selected key events. NPs: Nanoparticles; T_m: bulk melting points.