| 초록 |
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 oxidation of copper surfaces has been studied extensively in the literature -- from simple oxygen chemisorption structures to the formation of complex surface oxides and thin oxide films. 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 state-of-the-art ab initio scanning tunneling microscopy (STM) simulations that go beyond the simplistic Tersoff-Hamann's approach where the (functionalized) metal STM tips are explicitly included, and they are corroborated by precise single crystal growth methods (with ultra-low surface roughness) and high-resolution 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. |
