Rocking curves, X-ray diffraction

Fig. 28. X-ray diffraction rocking curve of (Ga.Mn)As/GaAs superlaltices with 20 periods (solid line). The nominal thicknesses of the GaAs and (Ga,Mn)As layers and the Mn composition x are 11.4 nm, 12.1 nm, and 0.0S4, respectively. The dashed line shows the simulated rocking curve. The fit to the experimental curve is obtained with GaAs and (Ga,Mn)As thicknesses and x of 11.14 nm, 11.79 nm, and 0.056, respectively (Shen...

Fig. 1 shows X-ray diffraction rocking curves for the as-prepared PS samples and the samples exposed to RTP. The peak from the initial PS layer is located at the left of the basic peak from the crystal silicon substrate indicating that the lattice parameter of the PS layer, measured normal to the surface, is greater than that of the Si substrate. The angular shift A0 between the two peaks is directly related to the perpendicular component of the mismatch Aa/a between porous and single silicon through the relation ... 

In this chapter we introduce high resolution diffraction studies of materials, beginning from the response of a perfect crystal to a plane wave, namely the Bragg law and rocking curves. We compare X-rays with electrons and neutrons for materials characterisation, and we compare X-rays with other surface analytic techniques. We discuss the definition and purpose of high resolution X-ray diffraction and topographic methods. We also give the basic theory required for initial use of the techniques. 

A7.10 X-ray diffraction characterisation of GaN-based materials rocking curve analysis... 

Finally, it is noted that the X-ray rocking curve for (111) diffraction line was 2.5°. This value is almost comparable to the corresponding value of HOD films, but much greater than the value of single crystal diamond, 0.03°. Part of the reason for this is that for the diamond-Pt case, the X-ray diffraction picked up the signals from diamonds near the interface, which are more randomly oriented. 

This instrument was much used in the early days of x-ray diffraction to compare the width and height of the rocking curve for a real crystal with the values predicted by theory for a perfect crystal [G.30]. This theory predicted a width of the order of 10 seconds (0.003°) for typical experimental conditions, and some crystals were found with rocking-curve widths approaching this value. However, most crystals exhibit widths 10 to 100 times greater. 

The effect of SiN deposition conditions on the epitaxial structural quality was characterized first by the full width at half-maximum (FWFIM) values of X-ray diffraction (XRD) (0002) and (1012)rocking curves. 

LSAT) substrate, (c) d-20 X-ray diffraction (XRD) measurement of the same sample. Substrates peak is labeled with a f). (d) Superimposed XRD rocking curves of the (0042 peak) and underiying LSAT substrate (002 peak). (Reproduced with permission from Ref. [27]. Copyright 2013, AlP Publishing LLC.)... 

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