Academic Journal
Statistical multiple diffuse scattering from rough surfaces in RHEED- beyond the distorted-wave Born approximation
| العنوان: | Statistical multiple diffuse scattering from rough surfaces in RHEED- beyond the distorted-wave Born approximation |
|---|---|
| المؤلفون: | Z. L. Wang |
| المساهمون: | The Pennsylvania State University CiteSeerX Archives |
| المصدر: | http://www.nanoscience.gatech.edu/zlwang/paper/1996/96_SS_2.pdf. |
| سنة النشر: | 1996 |
| المجموعة: | CiteSeerX |
| مصطلحات موضوعية: | Distorted wave-born approximation, Point defect, Reflection high-energy electron diffraction (RHEED, Shirt range order, Surface roughness, Thermal diffuse scattering |
| الوصف: | In reflection high-energy electron diffraction (RHEED) of growing surfaces in molecular beam epitaxy (MBE), diffuse scattering is generated by atom vibrations, point vacancies and growth islands (or surface roughness). Most of the existing RHEED theories have been developed under the first-order diffuse scattering approximation, and thus they are restricted for surfaces whose roughness is relatively low. In fact, crystal surfaces grown by MBE are usually rough; the change of surface coverage from 0 to 1 monolayer accounts for the observed RHEED oscillation. In this paper, a formal dynamical theory of RHEED has been developed to calculate the diffuse scattering produced by both atom vibrations and point vacancies at surfaces. The theory is aimed at recovering the multiple diffuse scattering that has been dropped by the distorted-wave Born approximation (DWBA). With the inclusion of a complex potential in the dynamical calculation, a rigorous proof is given to show that the high-order diffuse scattering terms are recovered in the calculation using the equation originally derived under the DWBA. This conclusion establishes the basis for expanding the RHEED theories developed under the first-order diffuse scattering to cases where the degree of surface roughness i high, allowing dynamical calculation of RHEED rocking curves for any growing surface. The statistical time and structure averages over the distorted crystal potential are evaluated analytically before numerical calculation. The dynamic form factor is calculated with consideration of anisotropic surface atom vibration and point vacancies at a growing surface. |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.536.9987; http://www.nanoscience.gatech.edu/zlwang/paper/1996/96_SS_2.pdf |
| الاتاحة: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.536.9987 http://www.nanoscience.gatech.edu/zlwang/paper/1996/96_SS_2.pdf |
| Rights: | Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
| رقم الانضمام: | edsbas.247174AC |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |