Computer Physics Communications Program Library

Programs in Physics & Physical Chemistry



Manuscript Title: An extension of the computer program for dynamical calculations of RHEED intensity oscillations. Heterostructures
Authors: Andrzej Daniluk
Program title: RHEED_v2
Catalogue identifier: ADUY_v1_1 Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 176(2007)70
Programming language: C++.
Computer: Pentium-based PC.
Operating system: Windows 9x, XP, NT, Linux.
RAM: more than 1 MB
Word size: 64 bits
Keywords: Reflection high-energy electron diffraction (RHEED), Heteroepitaxy, Scattering potential, Rocking curve, Computer simulations.
PACS: 02.60.Cb, 61.14.Hg.
Classification: 7.2, 8.
Does the new version supersede the previous version?: Yes
Nature of problem: Reflection high-energy electron diffraction (RHEED) is a very useful technique for studying the growth and the surface analysis of thin epitaxial structures prepared by the molecular beam epitaxy (MBE). The RHEED technique can reveal, almost instantaneously, changes either in the coverage of the sample surface by adsorbates or in the surface structure of a thin film.
Solution method: The new version of the program retains the design and structure of the previous one [1].
Reasons for new version: Responding to the user feedback we presented an extension of the RHEED program that enables computing the crystalline potentials for epitaxial heterostructures and corresponding values of the amplitude of the RHEED intensity oscillations.
Summary of revisions: The new version of the RHEED program has the same design as the previous one [1]. To simulate the structural variations of whole crystalline heterostructure along the surface normal direction the substrate and layers are divided into an assembly of n atomic layers. Each of these layers is further divided into an assembly of i thin slices parallel to the surface and each slice is assumed to have a constant potential normal to the surface as shown in Fig. 1. The Fourier component of the scattering potential of the whole crystalline heterostructure can be determined as a sum of contributions coming from all thin slices of n individual atomic layers. Figure 2 presents the crystalline potentials (real part) calculated for some Pb layers on a Si(111) substrate at 70 K. Figure 3 shows a dynamically calculated one-beam rocking curve for Pb/Si(111). The presented algorithm is a generalization of the previous one. By attributing 0 to the numberOfLayers and NLayers constant parameters (Fig. 4) and removing appropriate functions from the main program (Fig. 5), we obtain the same results as in the case of monocrystal [1].
Unusual features: The program is presented in the form of a basic unit RHEED_v2.cpp. It is not tied to any specific hardware and systems software platform, and could be compiled using C++ compilers, including C++Builder, VC++ and g++.
Additional comments: The Figures mentioned above are included in the distribution tar.gz file.
Running time: The typical running time is machine and user-parameters dependent.
References:
[1]	A. Daniluk, Comput. Phys. Comm. 166 (2005) 123.