MgO ultrathin films are of great technological importance as electron tunneling barrier in electronics and spintronics, and as template for metallic clusters in catalysis and for molecular networks for 2D electronics. The wide band-gap of MgO allows for a very effective decoupling from the substrate. The films morphology and the detailed structure of the interface are crucial for applications, controlling the electronic transfer. Using surface x-ray diffraction, we studied the growth-mode and the structure of MgO/Ag(001) ultrathin films elaborated by reactive molecular beam epitaxy as function of the substrate temperature. We observed that deposition of about 1 monolayer results in an MgO(001) film in coherent epitaxy, with the oxygen atoms on top of silver as predicted by DFT calculations, and an interlayer distance at the interface of about 270pm. Under well-defined conditions, a sharp MgO bilayer is formed covering a fraction of the substrate surface.

MgO 超薄膜在电子学和自旋电子学中作为电子隧道势垒具有重要的技术意义，并且作为催化中金属簇和二维电子学分子网络的模板。MgO 的宽带隙允许与衬底非常有效的去耦。薄膜形态和界面的详细结构对于控制电子转移的应用至关重要。使用表面 X 射线衍射，我们研究了反应分子束外延作为基板温度函数的 MgO/Ag(001) 超薄膜的生长模式和结构。我们观察到大约 1 个单层的沉积导致 MgO(001) 膜在相干外延中，如 DFT 计算所预测的，氧原子位于银的顶部，界面处的层间距约为270pm。在明确定义的条件下，形成锋利的 MgO 双层，覆盖基板表面的一小部分。