Difference between revisions of "Absorption edge"
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| − | <font color="blue">Arête d'absorption</font> (''Fr''). <font color="red">Absorptionskante</font> (''Ge''). <font color="black">Spigolo di assorbimento</font> (''It''). <font color="purple">吸収端</font> (''Ja''). <font color=" | + | <font color="blue">Arête d'absorption</font> (''Fr''). <font color="red">Absorptionskante</font> (''Ge''). <font color="black">Spigolo di assorbimento</font> (''It''). <font color="purple">吸収端</font> (''Ja''). <font color="brown">край поглощения</font> (''Ru''). <font color="green">Canto de absorción</font> (''Sp''). |
== Definition == | == Definition == | ||
Revision as of 16:09, 27 November 2017
Arête d'absorption (Fr). Absorptionskante (Ge). Spigolo di assorbimento (It). 吸収端 (Ja). край поглощения (Ru). Canto de absorción (Sp).
Definition
An absorption edge is the energy at which there is a sharp rise (discontinuity) in the (linear) absorption coefficient of X-rays by an element, which occurs when the energy of the photon corresponds to the energy of a shell of the atom (K, LI, LII, LIII, etc. corresponding to the creation of electron holes in the 122s22, 2s, 2p1/2, 2p3/2 etc. atomic subshells).
Associated with this transition is the absorption threshold (q.v.) characterized by the corresponding energy E0.
Examples
For gallium: [math]\lambda_{K}[/math] = 1.1958 Ǻ; [math]\lambda_{L_{I}}[/math] = 9.5446 Ǻ; [math]\lambda_{L_{II}}[/math] = 10.8414 Ǻ; [math]\lambda_{L_{III}}[/math]= 11.1038 Ǻ.
For arsenic: [math]\lambda_{K}[/math] = 1.0448 Ǻ; [math]\lambda_{L_{I}}[/math] = 8.1195 Ǻ; [math]\lambda_{L_{II}}[/math] = 9.1187 Ǻ; [math]\lambda_{L_{III}}[/math]= 9.3617 Ǻ.
See also
- Absorption threshold
- Fermi level
- Section 4.2.3 of International Tables for Crystallography, Volume C