Localized two-step galvanic replacement of a tip apex modification for field sensitive scanning probe microscopy

In this paper, a platinum-silver composite nano-dot (Pt@Ag ND) decorated tip apex was successfully fabricated by utilizing a localized two-step galvanic replacement. In the first replacement, Ag-ND tip was prepared by the replacement between silicon and silver ion through fluoride assisted galvanic replacement reaction. In the second replacement, the Ag ND was further changed to Pt by the interaction between Ag and chloroplatinic acid. Our preliminary results demonstrated the possibility of preparing either a single metal-nanodot (metal-ND) or core-shell structure modified tip apexes for field sensitive scanning probe microscopy (FS-SPM) applications.