Li J H, Moss S C, Zhang Y, Mascarenhas A, Pfeiffer L N, West K W, Ge W K, Bai J
Physics Department, University of Houston, Houston, Texas 77204-5005, USA.
Phys Rev Lett. 2003 Sep 5;91(10):106103. doi: 10.1103/PhysRevLett.91.106103.
We report studies of (GaAs)(n)/(AlAs)(n) ultrashort-period superlattices using synchrotron x-ray scattering. In particular, we demonstrate that interfaces of these superlattices contain features on two different length scales: namely, random atomic mixture and ordered mesoscopic domains. Both features are asymmetric on the two interfaces (AlAs-on-GaAs and GaAs-on-AlAs) for n>2. Periodic compositional stacking faults, arising from the intrinsic nature of molecular-beam epitaxy, are found in the superlattices. In addition, the effect of growth interruption on the interfacial structure is discussed. The relevant scattering theory is developed to give excellent fits to the data.
我们报告了使用同步加速器X射线散射对（GaAs）（n）/（AlAs）（n）超短周期超晶格的研究。特别地，我们证明这些超晶格的界面包含两种不同长度尺度的特征：即随机原子混合和有序介观域。对于n>2，这两种特征在两个界面（AlAs在GaAs上和GaAs在AlAs上）都是不对称的。在超晶格中发现了由分子束外延的固有性质引起的周期性成分堆垛层错。此外，还讨论了生长中断对界面结构的影响。发展了相关的散射理论以对数据进行出色的拟合。
