
The mystery and application of graphite curved crystal monochromator
2025-03-18 17:19The graphite curved crystal monochromator used in X-ray diffractometers is a key component for selecting specific wavelengths of X-rays and removing unwanted radiation such as K β lines and fluorescent X-rays. The graphite curved crystal monochromator is a component installed in front of the X-ray detector, which monochromatizes the X-rays passing through the receiving slit and only detects the Kα characteristic X-rays in the X-ray spectrum. By using this device, continuous X-rays, K β characteristic X-rays, and fluorescent X-rays can be completely eliminated, enabling high signal-to-noise ratio X-ray diffraction analysis. When copper target X-ray tubes are used in conjunction with corresponding monochromators, fluorescent X-rays generated from Mn, Fe, Co, Ni based samples can be eliminated, making them suitable for analysis of various samples.
working principle:
Bragg diffraction: Based on Bragg's law, when X-rays are incident on a crystal at a certain angle, if 2dsin θ=n λ (where d is the interplanar spacing of the crystal, θis the incident angle, λ is the wavelength of the X-ray, and n is an integer), diffraction will occur. It utilizes this principle to adjust the orientation of the crystal so that only X-rays that meet specific conditions can pass through, thereby achieving the selection of X-ray wavelengths.
Energy resolution: Due to the interplanar spacing and structural characteristics of graphite crystals, it can effectively distinguish X-rays of different energies. High energy resolution graphite curved crystal monochromator can further reduce unwanted radiation and improve the quality of diffraction data.
Structural features:
Curved shape: graphite curved crystal monochromator typically have a curved shape, which helps focus X-rays and improve diffraction efficiency. At the same time, the curved shape also helps to reduce the stress on the crystal, improve its stability and service life.
High purity graphite: Graphite curved crystal monochromator is usually made of high-purity graphite materials to ensure their good diffraction performance and stability.
High diffraction efficiency: It has a high diffraction efficiency, which can effectively select X-rays of the desired wavelength, thereby improving the quality of diffraction data.
Wide wavelength range: It can operate over a wide wavelength range and is suitable for various types of X-ray diffraction experiments.
Good stability: Due to the use of high-purity graphite material, it has good stability and a long service life.
Application areas:
Materials Science: In the field of materials science, X-ray diffractometers are widely used to study the crystal structure, phase composition, and other properties of materials. The graphite curved crystal monochromator, as an important component of X-ray diffractometer, provides important technical support for materials science research.
Physics: In the field of physics, X-ray diffractometers are also used to study the microstructure and physical properties of matter.
In summary, the graphite curved crystal monochromator used in X-ray diffractometers is an efficient and accurate X-ray selection and filtering device, providing important technical support for X-ray diffraction experiments.