This paper discusses chemical and galvanic corrosion of tungsten nitride carbide (WNC) barrier metal. Chemical corrosion occurs due to the oxidation of W in the WNC film by H2O2, which is used as oxidizer in CMP slurries, followed by the dissolution of the oxide complex. Galvanic corrosion takes place due to the high potential difference between Cu and WNC established in the presence of H2O2 ba...

While galvanic exchange is commonly applied to metallic nanoparticles, recently its applicability was expanded to metal-oxides. Here the galvanic exchange is studied in metal/metal-oxide core/shell nanocrystals. In particular Sn/SnO2 is treated by Ag+, Pt2+, Pt4+, and Pd2+. The conversion dynamics is monitored by in situ synchrotron X-ray diffraction. The Ag+ treatment converts the Sn cores to ...

Coupling seed-mediated co-reduction with galvanic replacement for the first time provides a route to trimetallic (Ag-Au-Pd) nanostructures with hollow interiors. Moreover, manipulating the synthetic conditions can suppress galvanic replacement and facilitate formation of trimetallic core@shell (Ag@Au-Pd) nanostructures. These results illustrate the role of seed composition in the synthesis of a...

This paper analyzes the effect of sliding speed on electrical conductivity and friction properties contact pair an on-load tap changer (OLTC). Reciprocating current-carrying tribological tests were carried out a rod–plate–copper–tin–copper galvanic couple at different speeds in air insulating oil media. The results show that as increases from 24 mm/s to 119 mm/s, average resistance 0.2 ? 0.276 ...

Biocompatible materials used for the fabrication of dental crowns were studied. Patients were treated with Gold, Porcelain and Zirconia crowns. Dental crowns were selected according to patient’s clinical status and needs. We found that Gold crowns had low patient acceptance because of poor aesthetics and high cost. Gold crowns could not be used opposite to amalgam restorations for the fear of g...

The realization of common materials transformations in nanocrystalline systems is fostering the development of novel nanostructures and allowing a deep look into the atomistic mechanisms involved. Galvanic corrosion is one such transformation. We studied galvanic replacement within individual metal nanoparticles by using a combination of plasmonic spectroscopy and scanning transmission electron...

Iron and manganese are relevant constituents of the earth's crust and both show increasing mobility when reduced by free electrons. This reduction is known to be controlled by microbial dissimilation processes. Alternative sources of free electrons in nature are cloud-to-ground lightning events with thermal and galvanic effects. Where thermal effects of lightning events are well described, less...