7/14/2023 0 Comments Peak splitting xray diffraction![]() An XRD reciprocal space map performed on the (105) plane shows that one component of the partially resolved InGaN double peak is almost aligned with that of the GaN buffer, indicating that part of the layer is pseudomorphic to the GaN template. In this report, a detailed characterisation of a InGaN/GaN bilayer by a combination of XRD and Rutherford backscattering spectrometry (RBS) shows that splitting of the XRD peak may occur in the absence of phase decomposition. N2 - The observation of multiple, X-ray diffraction (XRD) and photoluminescence (PL) peaks in an InGaN epilayer is sometimes regarded as an indicator of phase segregation. T1 - Splitting of X-ray diffraction and photoluminescence peaks in InGaN/GaN layers Furthermore, PL spectroscopy shows a double peak that can be accounted for by regions of the sample under different strains.", Depth-resolving RBS/channelling angular scans also shows that the region closer to the GaN/InGaN interface is nearly pseudomorphic to the GaN substrate, whereas the surface region is almost fully relaxed. The layer composition deduced from XRD measurements is confirmed by RBS. From a consideration of the effect of strain on the c- and a-lattice constants, both the partially relaxed and the pseudomorphic components are shown to have the same indium content. Furthermore, PL spectroscopy shows a double peak that can be accounted for by regions of the sample under different strains.Ībstract = "The observation of multiple, X-ray diffraction (XRD) and photoluminescence (PL) peaks in an InGaN epilayer is sometimes regarded as an indicator of phase segregation. Single molecular layer MoS 2 and WS 2 suspensions, prepared by exfoliation, provide excellent randomly oriented two‐dimensional systems for demonstrating the unique features of powder x‐ray diffraction patterns of two‐dimensional materials and for structure identification using Bragg peak profiles.The observation of multiple, X-ray diffraction (XRD) and photoluminescence (PL) peaks in an InGaN epilayer is sometimes regarded as an indicator of phase segregation. It is demonstrated that because of structure factor modulation the Warren expression which relates the width of Bragg peaks to layer size cannot be used for a two‐dimensional sheet with more than one layer of atoms, and it is proposed in such cases that measuring the low‐angle side width of half‐maximum intensity can be used for determination of the layer size. This structure factor modulation provides a continuous plot of the structure factor over the range of the diffraction tail and thus provides valuable information about the structure of the layer. For a two‐dimensional structure consisting of more than one monolayer of atoms, the shape of the Bragg peaks is modulated by the structure factor. The analytic solution, where the Bragg peaks are strongly asymmetric, is compared to computer simulations using the Debye formula, and is shown to be in closer agreement than earlier numerical solutions by Warren and others. An analytic solution for the normalized intensity for powder x‐ray diffraction has been obtained for a simple two‐dimensional lattice using a linear approximation for the interference function. ![]()
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