Plasmamodifikation bimetallischer Nanokolloidkristalle zur Erzeugung chemisch aktiver dünner Schichten

Abstract

Self-assembled layers of bimetallic Co-Pt alloy nanocolloids were prepared from suspension to act as model systems for chemically active surface coatings. A compact, versatile and easy to maintain rf plasma source was constructed to serve as a tool for cleaning and non-destructive surface modification of the deposited particle arrays while avoiding sample contamination from atmospheric exposure. It was shown that the original shell of passivating ligands can be completely removed using a sequence of oxygen and hydrogen plasmas while preserving the shape and size of the individual particles with only minor effects on layer ordering. The plasma modification of the particle surfaces however results in hydrogen loaded surfaces with a remaining fraction of oxidic cobalt dominating the surface chemistry after annealing. While the plasma treatment preserves the sample structure during ligand removal it causes complex constrains in the choice of the materials system components.