Completing the picture of initial oxidation on copper

Accurate atomistic models for metal/oxide interfaces play a pivotal role in determining copper-based interfacial processes, ranging from electronic circuitry wirings to chemical catalysis. The 29 and 44 surfaces represent two of the most classical embryonic oxides on Cu(111). Although many attempts have been made to offer detailed atomistic models of these surface oxides, their atomic structures remain elusive. Here, we address this open question via ab initio STM simulations, where the functionalized-metal tips are explicitly included, and they are corroborated by STM experiments. We find that the fine structures of STM images of the 29 and 44 surfaces are correctly captured with STM theories going beyond the Tersoff-Hamann approximation only. Furthermore, we elucidate a complete atomistic model for the larger 44 surface, completing the picture of early oxidation on copper.

Automated summary

Accurate atomistic models for metal/oxide interfaces are crucial for understanding copper-based interfacial processes, and in this study, the atomic structures of the 29 and 44 surfaces on Cu(111) are successfully revealed through ab initio STM simulations and experiments. A complete atomistic model for the larger 44 surface is elucidated, providing further insights into early oxidation on copper.