Electric-field-induced low temperature oxidation of tungsten nanowires

Experiments on the room temperature oxidation of tip-shaped tungsten nanowires under an externally applied electric field are reported, yielding the controlled formation of tungsten oxide layers up to several tens of nanometers thick in the high field region at the tip of the nanowires. The initially very fast oxidation reaction is observed to virtually terminate at a field dependent state, defined by a critical field strength of 1.15(2)×109V∕m. Since electric fields of the order of 109V∕m are easily obtained, the observed effect may influence the chemical stability of nanoscaled systems significantly when used in ambient atmosphere.