Reaction of Copper and Copper Oxide with  H ₂ S 

The lack of sulfidation of copper in indoor atmospheric corrosion has been attributed to the formation of copper oxide on copper, i.e., the oxide which forms on the copper surface initially inhibits the growth of corrosion (sulfide films) on the surface. A permeation tube apparatus has been constructed with a quartz crystal microbalance (sensitivity ∼10⁻⁸g) to elucidate the reaction of copper and copper oxide with . The film composition was measured with ESCA and Auger spectroscopy and the film thickness was measured with the quartz crystal microbalance to avoid the ambiguity of thickness estimation from sputter rate measurements in depth profiling. Results indicate that copper oxides grown in air (several hundred Å thick) provide good protection against at low relative humidities, but little protection at high relative humidities. Oxides grown in pure oxygen provide more protection, but still tarnish rapidly at higher relative humidities.