Anomalous small-angle X-ray scattering of nanoporous two-phase atomistic models for amorphous silicon-germanium alloys

被引:2
作者
Chehaidar, A. [1 ]
机构
[1] Univ Sfax, Fac Sci, Dept Phys, Lab Phys Math & Applicat, Sfax 3000, Tunisia
关键词
Amorphous silicon-germanium; Nanoheterogeneity; Small-angle X-ray scattering; Anomalous small-angle X-ray scattering; Modelling; ABSORPTION FINE-STRUCTURE; MICROSTRUCTURAL ANALYSIS; A-SIGE; INHOMOGENEITIES; DIFFRACTION; DYNAMICS; ORDER; FILMS; GE;
D O I
10.1016/j.matchar.2015.06.031
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The present work deals with a detailed analysis of the anomalous small-angle X-ray scattering in amorphous silicon-germanium alloy using the simulation technique. We envisage the nanoporous two-phase alloy model consisting in a mixture of Ge-rich and Ge-poor domains and voids at the nanoscale. By substituting Ge atoms for Si atoms in nanoporous amorphous silicon network, compositionally heterogeneous alloys are generated with various composition-contrasts between the two phases. After relaxing the as-generated structure, we compute its radial distribution function, and then we deduce by the Fourier transform technique its anomalous X-ray scattering pattern. Using a smoothing procedure, the computed X-ray scattering patterns are corrected for the termination errors due to the finite size of the model, allowing so a rigorous quantitative analysis of the anomalous small-angle scattering. Our simulation shows that, as expected, the anomalous small-angle X-ray scattering technique is a tool of choice for characterizing compositional heterogeneities coexisting with structural inhomogeneities in an amorphous alloy. Furthermore, the sizes of the compositional nanoheterogeneities, as measured by anomalous small-angle X-ray scattering technique, are X-ray energy independent. A quantitative analysis of the separated reduced anomalous small-angle X-ray scattering, as defined in this work, provided a good estimate of their size. (C) 2015 Elsevier Inc. All rights reserved.
引用
收藏
页码:54 / 62
页数:9
相关论文
共 40 条
[1]   Ab initio models of amorphous Si1-xGex:H [J].
Abtew, T. A. ;
Drabold, D. A. .
PHYSICAL REVIEW B, 2007, 75 (04)
[2]   High-quality continuous random networks [J].
Barkema, GT ;
Mousseau, N .
PHYSICAL REVIEW B, 2000, 62 (08) :4985-4990
[3]   Comparison between X-ray absorption spectroscopy, anomalous wide angle X-ray scattering, anomalous small angle X-ray scattering, and diffraction anomalous fine structure techniques applied to nanometer-scale metallic clusters [J].
Bazin, DC ;
Sayers, DA ;
Rehr, JJ .
JOURNAL OF PHYSICAL CHEMISTRY B, 1997, 101 (51) :11040-11050
[4]   Small-angle X-ray scattering of two-phase atomistic models for amorphous silicon-germanium alloys [J].
Ben Brahim, R. ;
Chehaidar, A. .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 2015, 416 :4-13
[5]   Microstructural analysis of nanostructured amorphous silicon-germanium alloys: Numerical modeling [J].
Ben Brahim, R. ;
Chehaidar, A. .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 2011, 357 (14) :2620-2625
[6]   Microstructural analysis of atomistic models of Si-rich amorphous silicon-germanium alloys [J].
Ben Brahim, R. ;
Chehaidar, A. .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 2011, 357 (6-7) :1531-1537
[7]   Structural and optoelectronic properties of silicon germanium alloy thin films deposited by pulsed radio frequency plasma enhanced chemical vapor deposition [J].
Bhaduri, A. ;
Chaudhuri, P. ;
Williamson, D. L. ;
Vignoli, S. ;
Ray, P. P. ;
Longeaud, C. .
JOURNAL OF APPLIED PHYSICS, 2008, 104 (06)
[8]   Correlation of structural inhomogeneities with transport properties in amorphous silicon germanium alloy thin films [J].
Bhaduri, Ayana ;
Chaudhuri, Partha ;
Vignoli, Stephane ;
Longeaud, Christophe .
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 2010, 94 (09) :1492-1495
[9]  
Brahim R., 2013, ADV MAT PHYS CHEM, V3, P19, DOI DOI 10.4236/AMPC.201331A003
[10]   Short-range compositional randomness of hydrogenated amorphous silicon-germanium films [J].
Chapman, BD ;
Han, SW ;
Seidler, GT ;
Stern, EA ;
Cohen, JD ;
Guha, S ;
Yang, J .
JOURNAL OF APPLIED PHYSICS, 2002, 92 (02) :801-807