Nitrogen Adsorption on Cu(001): Mechanisms of Stress Relief and Coexistence of Two Domains

We have studied nanometer-scale features observed with scanning tunneling microscopy on nitrogen (N)-adsorbed Cu(001) surfaces. Grid-like nanopattern aligned in [100] directions at a medium N-coverage and trenches along [110] appearing higher are frequently reported. In addition, we “diagonal lines” grid-patterned surface “dark curves” growing from the trench ends. All above responsible for relief of N-induced compressive stress. propose structural models five features, based hard-sphere model, estimate how much strain is absorbed by feature. Nitrogen atoms adsorbed c(2 × 2) arrangement. Since two energetically-equivalent arrangements possible, N-adsorbed domains can be “in-phase” or “antiphase” direction domain boundary. show also that each strain-relief feature has specific preference phases. Looking out over mechanisms, note that, N coverage is, more effective mechanism chosen, “monoatomic line” (a component grid) very unique since it formed between in-phase domains.