 | Acta Crystallographica Section A Acta Crystallographica Section A FOUNDATIONS AND ADVANCES |
journal menu
![[Figure 7]](ae5046fig7mag.jpg)
|
|
Figure 7
(a) A diffraction space map close to the 004 reflection (logarithmic scale) from an InGaAs structure grown epitaxially on a GaAs substrate. The data were collected with the beam selection diffractometer (Fewster, 2004  ), with a single reflection 004 analyser crystal (stepping in Ω followed by a scan with movements in Ω and 2θ maintaining a 1:2 ratio). The strong fringing is associated with the layer structure (the shape transform) and occurs along the crystal surface normal. The streak where 2θ = 2Ω corresponds to the incident-beam divergence and the streak along 2θ for a constant Ω value corresponds to the detector acceptance range (in this case the diffraction profile of the analyser crystal). The remaining streak at constant 2θB for varying Ω values is the `enhancement' peak for the substrate (as in Fig. 5b). (b) This is the extracted profile along the 2θB enhancement that is smoothly decreasing from the peak as expected, apart from interference of the Cu Kα2 streak on the high-angle side. If all the artefacts could be removed and the alignment improved, this could be considered as the thickness profile of the Ewald sphere surface for this reflection and crystal. |
![[Figure 7]](ae5046fig7.jpg)
| FOUNDATIONS ADVANCES |
ISSN: 2053-2733
Open 
access
access
