X-ray spectroscopy
(rus. спектроскопия, рентгеновская)
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a method to study composition of matter by spectra of absorption or emission of photons with a wavelength in the X-ray range.
Description
Similar to other spectroscopic techniques, X-ray spectroscopy is used to study the structure of matter by spectra of absorption or emission of light during the transition of electrons from one energy state to another. The specific character of this method is that X-ray spectra are related to transitions of atoms' inner shell electrons. X-ray absorption spectra are caused by transitions of electrons from lower to higher (the so-called "excited") energy states, and X-ray emission spectra – from excited states to lower ones.
Absorption spectra can be used to obtain information about vacant excited states of chemical compounds or conduction bands of semiconductors. Application of the EXAFS (extended X-ray absorption fine structure) method makes it possible to determine such parameters of matter as interatomic distances even in amorphous bodies which can not be studied by the X-ray diffraction method.
Absorption spectra can be used to obtain information about vacant excited states of chemical compounds or conduction bands of semiconductors. Application of the EXAFS (extended X-ray absorption fine structure) method makes it possible to determine such parameters of matter as interatomic distances even in amorphous bodies which can not be studied by the X-ray diffraction method.
Illustrations
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Fig. 1. The scheme of electrons excitation and relaxation in ionizing radiation: а — photoelectron emission; b — x-ray absorption; c — x-ray fluorescence; d — auger process [1]. |
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Fig. 2. An overview of spectra of : а — photoelectrons; b — x-ray absorption; c — x-ray fluorescence; d — auger electrons [1]. |
Author
- Sergey Lourie
Source
- Pentin Yu. A., Vilkov L. V. Physical Methods in Chemistry. Textbook (in Russian) // Moscow: Mir, 2003. - 683 p.