Instrument for crystal structure analysis - X-ray diffraction spectrum
2024-01-24 00:00X-ray diffraction spectrum mainly analyzes the crystalline state and microstructure of the material, because the wavelength of the X-ray is similar to the lattice constant of the crystal, irradiated on the crystalline material, and the diffraction pattern generated by the analysis can determine the atomic structure and crystal type. There are two X-ray diffraction measurements for crystal analysis.
1.X-ray diffraction spectrum method, X-ray difractometer basic structure has three parts: X-ray source, goniometer, detector.
Usually, the X-ray source is produced by using an electron beam to impinge A copper target. Ka-characteristic X-ray is measured by a single frequency selector. Cu-KaX optical wavelength is 1.542A, resulting in an X-ray diffraction spectrum. Take the single crystal diffraction pattern as shown in the figure on the right. The product plane direction (400) is obtained from the diffraction crest Angle compared with the powder crystal diffraction standard chart. The stronger the crest intensity and the narrower the half-height width, the better the product characteristics.
2. X-ray back reflection Laue method
X-ray reflection Laue method is a spectrum obtained by using X-ray irradiation of crystals. X-ray irradiation on a fixed silicon single wafer will produce diffraction phenomenon at certain angles according to Bragg's law, as shown in the figure on the left, and the diffraction pattern of (100) single crystal reflection Laue is shown in the figure on the right. This method can be used to distinguish the crystal direction of a single crystal.