As an advanced material analysis technology, X-ray absorption fine structure spectrometer has shown great potential and value in multiple fields such as materials science, chemistry, biology, and medicine since its inception.
1、 Working principle
Its working principle is based on the interaction between X-rays and specific elements in matter. When X-rays pass through a sample, specific energy rays are absorbed by atoms in the sample and trigger electron transitions, resulting in the emission of X-rays of specific wavelengths. These emitted X-rays carry important information about the atomic structure and electronic state of the sample. By finely regulating X-ray energy to excite electronic transitions of specific elements in the sample, and measuring the energy and intensity of these X-rays, scientists can obtain rich information on material structure.
Specifically, XAFS technology utilizes the absorption process of X-rays in materials to analyze the fine structure of samples by measuring the variation of absorption coefficient μ with energy E (i.e., μ (E) curve). When X-rays are absorbed by matter, they produce photoelectrons (outgoing waves), which scatter through surrounding atoms to form scattered waves. Two waves with different phases interfere at the absorbing atom, thereby affecting the photoelectron wave function at the absorbing atom, i.e. the absorption coefficient μ. By analyzing the shape, position, and intensity of the μ (E) curve, scientists can decipher key information such as the valence state of the element, coordination environment, chemical bond type, and local electronic structure.
2、 Technical features
1. Strong element resolution capability: XAFS technology has excellent element resolution capability, which can accurately determine the structural information of specific elements in different forms of substances such as solid, liquid, and gas. This makes XAFS technology significantly advantageous in the analysis of neighboring local structures and valence states of elements in complex systems.
2. Non destructive testing: XAFS technology is a non-destructive testing method that can obtain internal structural information of a sample without damaging it. This is particularly important for precious samples or samples that are difficult to prepare.
3. Low sample demand: The sample size required for X-ray absorption fine structure spectrometer testing is very small, usually only a few milligrams or even less of sample are needed to obtain high-resolution results. This greatly reduces testing costs and time, and improves testing efficiency.
4. High measurement accuracy: With the advancement of technology, its performance continues to improve, such as higher energy resolution, faster scanning speed, and lower detection limits. These advancements have further expanded the application areas of XAFS, improving the accuracy and reliability of measurements.
3、 Application Fields
1. Materials Science: In the field of materials science, XAFS technology is widely used to study the crystal structure, electronic states, and elemental distribution of materials. Through XAFS technology, scientists can gain a deeper understanding of the relationship between the composition, structure, and properties of materials, providing powerful support for material design and optimization. For example, in the field of catalyst research, the coordination environment and electronic state of the active center of the catalyst can be revealed, providing key information for the design and improvement of catalysts.
2. Chemistry: In the field of chemistry, it is used to reveal the mechanisms of chemical reactions and the structural changes of substances during the reaction process. By measuring the XAFS spectra of reactants, intermediates, and products, scientists can decipher reaction pathways and mechanisms, providing guidance for the control and optimization of chemical reactions. In addition, it can also be used to study biological problems such as the spatial conformation and interaction mechanisms of biomolecules.
3. Environmental science: In the field of environmental science, it is used to analyze the types, forms, and contents of pollutants in environmental samples. Due to its strong element resolution ability and low sample demand, XAFS technology is particularly suitable for studying the distribution and morphological changes of elements in complex systems in nature. For example, precise determination and analysis of heavy metal elements, organic pollutants, etc. can be achieved in environmental media such as soil, water, and atmosphere.
4. Medicine: In the field of medicine, it is also used to study the interaction mechanisms between metal elements and biomolecules in living organisms, as well as the occurrence and development of diseases. By measuring the XAFS spectra of biological samples, scientists can obtain information about the coordination environment and electronic state of metal elements in the body, providing new avenues and methods for disease diagnosis and treatment.