X-ray diffraction (XRD) is a powerful non-destructive technique for characterizing crystalline materials. It provides information on structures, phases, preferred crystal orientations (texture), and other structural parameters, such as average grain size, crystallinity, strain, and crystal defects. X-ray diffraction peaks are produced by constructive interference of a monochromatic beam of X-rays scattered at specific angles from each set of lattice planes in a sample. The peak intensities are determined by the distribution of atoms within the lattice. Consequently, the X-ray diffraction pattern is the fingerprint of periodic atomic arrangements in a given material.
X-ray diffraction (XRD) is a basic tool in the mineralogical …show more content…
As the sample and detector are rotated, the intensities of diffracted X-rays are recorded. When Bragg’s equation is satisfied, it means that the geometry of diffracted X-rays shows constructive interference and peak shows up in the diffractogram. The detector, which is present inside the diffractogram, records that intensity. This intensityis then converted into a count rate, which is displayed and recorded into the monitor. The geometry of the diffractometer is such that the sample rotates the X-rays beam at an angle of θ, whereas X-rays, which are diffracted, rotates an angle of 2θ. The goniometer rotates the sample and …show more content…
Identification of fine-grained minerals such as clays and mixed layer clays that are difficult to determine optically. Determination of unit cell dimensions. Measurement of sample purity.
4.5 Requirements for an Ideal XRD
Reduction of the sample size is one of the chief considerations of the sample preparation. The number of the diffracting particles is inversely related to their size. The sample size should be small enough so that it fits in the sample holder and the surface of the sample should not be rough and irregular. It should be made smooth so that we have better results in our experiment.
4.6 Qualitative Phase Analysis
Each X-ray diffraction pattern has a unique set of Bragg peaks
• Peak positions are defined by the unit cell.
• Peak intensities result from the distribution of atoms