pulverröntgendiffraktion

Pulverröntgendiffraktion, often abbreviated as XRD, is an analytical technique used for determining the crystal structure of a solid material. The method relies on the principle of diffraction, where X-rays are scattered by the regularly spaced atoms within a crystal lattice. When a beam of monochromatic X-rays strikes a powdered sample, the X-rays are diffracted in specific directions according to Bragg's Law. This law states that constructive interference occurs when the path difference between scattered waves is an integer multiple of the wavelength of the X-rays.

The diffracted X-rays are detected, typically by a scintillation counter or a solid-state detector, as a function of the scattering angle (2θ). The resulting pattern is a series of peaks, each corresponding to a particular set of crystal planes within the material. The positions of these peaks are characteristic of the d-spacing (interplanar distance) and the angles between them, which are directly related to the unit cell dimensions and symmetry of the crystal. The intensities of the peaks are related to the arrangement and type of atoms within the unit cell.

Analysis of the XRD pattern allows for the identification of crystalline phases present in the sample, as well as the determination of their relative amounts. It can also provide information about crystallite size, strain, and texture. XRD is a non-destructive technique and is widely used in various fields, including materials science, chemistry, mineralogy, and pharmaceuticals, for quality control, research, and development.