Nanoscale duplex oxide growth during early stages of oxidation of Cu-Ni(100)

Abstract

for pure metals hold during the initial oxidation of Cu-Ni alloys. Our ex situ TEM observation of oxidized Cu-Ni samples revealed that Cu2O islands nucleate preferentially on top of NiO islands rather than on bare Cu-Ni surface regions between NiO islands, an intriguing phenomenon defying the expectation based on prevailing knowledge of passivation. Our results demonstrate the importance of oxygen partial pressure in controlling the microstructure of oxide films during alloy oxidation, which have significant technological implications for controlled oxide growth.