Quantitative Analysis: If the sample is not a pure substance, but consists of several components, it is also possible to calculate the relative amounts of the individual phases.Comparison of the obtained data with databases results in the identification of the material. This can be seen as the fingerprint of the sample. Qualitative Analysis: Every crystalline material produces a specific diffractogramm.Obtainable information from a diffractogramm: This is a plot of X-ray intensity on the y-axis versus the angle 2θ (2θ is defined as the angle between the incident and the diffracted beam) on the x-axis. The result of the measurement is a so called diffractogramm. As the wavelength in XRD experiments is known and the angles at which constructive interference occurs are measured, the use of the Bragg equation allows determining the distance between the lattice planes of the material. In words this equation can be described as follows: constructive interference occurs only if the path difference (given by 2d sinθ) is a multiple (n=1,2.) of the used wavelength of the X-ray beam. This is summarized in the famous Bragg – Equation: The magnitude of this path length only depends on the distance between the crystal planes and the incident angle of the X-ray beam. The resulting diffracted X-rays therefore have a different optical path length to travel. The incident X-ray beam is scattered at different planes of the material. Due to the crystalline nature, the atoms are arranged periodically. The dots in the graph correspond to the building blocks of a crystalline material. This is schematically shown in the next picture. This means that detectors can read-out a signal only at angles where constructive interference occurs. The scattered X-rays from the sample interfere with each other either constructively or destructively.
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