X-ray scattering is a technique that uses X-rays to study the structure and composition of materials. It is based on the scattering of X-rays by the atoms in a sample when it is irradiated with X-rays. The scattering of X-rays is affected by the atomic arrangement, density, and composition of the sample, and can provide information about the material's microstructure and physical properties.
There are two main types of X-ray scattering techniques: elastic scattering and inelastic scattering. Elastic scattering, also known as X-ray diffraction, occurs when the X-rays are scattered by the sample without any loss of energy. This type of scattering is used to study the crystal structure of materials and can provide information about the spacing and arrangement of atoms in a sample. Inelastic scattering, on the other hand, occurs when the X-rays transfer some of their energy to the sample, leading to the excitation of atoms or the creation of new particles. This type of scattering can provide information about the electronic structure and dynamics of a material.
Elastic scattering or X-ray diffraction
X-ray diffraction is based on the Bragg's Law, which states that the angle of diffraction is related to the spacing between planes of atoms in the sample. When a beam of X-rays is incident on a sample, it is scattered by the atoms in the sample according to the Bragg's Law. The intensity of the scattered X-rays is a function of the atomic spacing and the arrangement of atoms in the sample, and can be measured using a detector.
X-ray diffraction is a powerful technique for studying the crystal structure of materials and can provide information about the lattice spacing, unit cell dimensions, and symmetry of the crystal. It is widely used in materials science and engineering, as well as in biology, chemistry, and physics, to study the structure and properties of materials at the atomic and molecular level.
- Small-angle X-ray scattering (SAXS) probes structure in the nanometer to micrometer range by measuring scattering intensity at scattering angles 2θ close to 0°.
- X-ray reflectivity is an analytical technique for determining thickness, roughness, and density of single layer and multilayer thin films.
- Wide-angle X-ray scattering (WAXS), a technique concentrating on scattering angles 2θ larger than 5°.
Inelastic X-ray scattering is a type of X-ray scattering that occurs when the X-rays transfer some of their energy to the sample, leading to the excitation of atoms or the creation of new particles. This type of scattering can provide information about the electronic structure and dynamics of a material.
Inelastic X-ray scattering techniques include X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES), and X-ray Raman scattering (XRS).
- X-ray absorption spectroscopy (XAS) measures the absorption of X-rays by a sample as a function of energy. It is used to study the electronic structure of a material and can provide information about the valence states and bonding of atoms in the sample.
- X-ray emission spectroscopy (XES) measures the emission of X-rays by a sample after it has been excited by an incident beam of X-rays. It is used to study the electronic structure of a material and can provide information about the valence states and bonding of atoms in the sample.
- X-ray Raman scattering (XRS) is a form of inelastic scattering that occurs when an X-ray photon excites an electron in a material, leading to the emission of a scattered X-ray photon with a different energy. It is used to study the vibrational and phonon modes of a material and can provide information about the lattice dynamics and thermal properties of the sample.
Inelastic X-ray scattering techniques are powerful tools for studying the electronic and vibrational properties of materials at the atomic and molecular level, and can provide information that is not accessible through other techniques.
Comments
Post a Comment