Abstract Strong interaction between metal atoms and adsorbates sometimes leads to the formation of surface compounds. In such cases, the registry with a metal substrate plays a key role in determining the overlayer stability. In this paper, we present a structural model for a hexagonal Fe-N monolayer grown on a square Cu(001) substrate. The system exhibits a stripe pattern composed of dark (1 × 1) stripes (A-stripes) and bright ( 3 × 3 ) stripes (B-stripes). We suppose the FeN stoichiometry and the structure similar to a single (111) layer of zincblende type γ″-FeN. Based on protrusion alignment observed by scanning tunneling microscopy (STM), we propose that the A-stripe has a relaxed hexagonal lattice composed of equilateral Fe triangles with N atoms at the center whereas the B-stripe has a uniaxially-compressed lattice composed of isosceles Fe triangles. Connection of these two lattice with small inclination produces zigzag Fe-atom rows embedded in [110] troughs on the Cu(001) substrate. Thus, the FeN overlayer is commensurate with Cu(001) along the [ 1 ¯ 10] direction. The ( 3 × 3 ) reconstruction in B-stripes effectively relieves the compressive stress. Our model shows the way in which a stable overlayer exists on the substrate of different symmetry and lattice constants by forming a stripe pattern.

中文翻译：

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Cu(001) 上的六方氮化铁单层：锯齿形线槽排列

摘要 金属原子与被吸附物之间的强相互作用有时会导致表面化合物的形成。在这种情况下，金属基材的注册在确定覆盖层稳定性方面起着关键作用。在本文中，我们提出了在方形 Cu(001) 衬底上生长的六边形 Fe-N 单层的结构模型。该系统表现出由暗 (1 × 1) 条纹 (A 条纹) 和亮 (3 × 3 ) 条纹 (B 条纹) 组成的条纹图案。我们假设 FeN 的化学计量和结构类似于闪锌矿型 γ″-FeN 的单 (111) 层。基于通过扫描隧道显微镜（STM）观察到的突起排列，我们提出，A 条带具有由等边 Fe 三角形组成的松弛六边形晶格，其中 N 原子位于中心，而 B 条带具有由等腰 Fe 三角形组成的单轴压缩晶格。这两个具有小倾角的晶格的连接产生了嵌入 Cu(001) 衬底上的 [110] 槽中的锯齿形 Fe 原子行。因此，FeN 覆盖层沿 [ 1 ¯ 10] 方向与 Cu(001) 相称。B-stripes中的（3×3）重建有效地减轻了压应力。我们的模型通过形成条纹图案显示了在不同对称性和晶格常数的基板上存在稳定覆盖层的方式。FeN 覆盖层沿 [ 1 ¯ 10] 方向与 Cu(001) 相称。B-stripes中的（3×3）重建有效地减轻了压应力。我们的模型通过形成条纹图案显示了在不同对称性和晶格常数的基板上存在稳定覆盖层的方式。FeN 覆盖层沿 [ 1 ¯ 10] 方向与 Cu(001) 相称。B-stripes中的（3×3）重建有效地减轻了压应力。我们的模型通过形成条纹图案显示了在不同对称性和晶格常数的基板上存在稳定覆盖层的方式。