Ru and RuO₂ as Electrical Contact Materials: Preparation and Environmental Interactions

Ruthenium and ruthenium dioxide, an electronic conductor, have been evaluated as electrical contact materials for low voltage, low force contacts, and separable connectors. The contact resistance (CR) of bulk is 1 mΩ, only slightly higher than that of gold or ruthenium. A technologically more feasible contact, titanium coated with , has been developed and has a CR of less than 15 mΩ. Environmental studies show that both Ru and are reasonably stable at temperatures at least as high as 90°C and at all relative humidities, even in the presence of 1 ppm or flowers of sulfur vapor. Unlike other contact materials, sulfidation appears to be retarded by the presence of a high relative humidity.