Influence of Co contents on the microstructure and SERS performance of self-formed Ag nanoparticles/Ag-Co alloy films on flexible substrates

Microstructure Evolution of Ag/Ta Nanostructured Films for Surface-Enhanced Raman Scattering Substrates

“…In addition, the lattice spacing of Ag(111) in Ta–Ag alloy films is obviously narrower than that in pure Ag films, as shown in Figure c2,d2. This can be attributed to the fact that the addition of Ta increases the residual stress in the Ta–Ag alloy films and thus affects the lattice spacing of Ag(111), which is similar to the reduction of Ag(111) lattice spacing due to the addition of Co in Ag–Co alloy films . It should be emphasized that the Ag grains in pure Ag films are interconnected, while the Ag grains in Ta–Ag alloy films are dispersed and smaller than those in pure Ag films, and the area occupied by Ag grains is reduced because amorphous Ta takes up a significant portion of the alloy films, as shown in Figure c1,d1.…”

“…This can be attributed to the fact that the addition of Ta increases the residual stress 27 in the Ta−Ag alloy films and thus affects the lattice spacing of Ag(111), which is similar to the reduction of Ag(111) lattice spacing due to the addition of Co in Ag−Co alloy films. 28 It should be emphasized that the Ag grains in pure Ag films are interconnected, while the Ag grains in Ta− Ag alloy films are dispersed and smaller than those in pure Ag Pure Ag films exhibit a smooth surface without any particles, whereas a large number of Ag nanoparticles form on the Ta−Ag alloy film's surface, indicating that Ta is the primary reason for the formation of Ag nanoparticles. The results in Figure 2c,d show that the amorphous Ta inside Ta−Ag alloy films reduces the size of Ag grains and limits the diffusion of Ag atoms within the alloy films.…”