Atomic scattering factor - Revision history

BrianMcMahon: Tidied translations and added German (U. Mueller)

2017-11-08T18:09:24Z

Tidied translations and added German (U. Mueller)

BrianMcMahon: Style edits to align with printed edition

2017-05-12T12:34:00Z

Style edits to align with printed edition

MassimoNespolo: /* See also */ unordered list for references. Also, section title

2016-04-14T11:48:24Z

‎See also: unordered list for references. Also, section title

MassimoNespolo: languages

2016-04-14T11:46:43Z

languages

BrianMcMahon at 14:12, 10 April 2008

2008-04-10T14:12:18Z

BrianMcMahon at 12:12, 1 April 2008

2008-04-01T12:12:47Z

AndreAuthier at 15:52, 31 March 2008

2008-03-31T15:52:14Z

BrianMcMahon at 11:40, 31 March 2008

2008-03-31T11:40:28Z

BrianMcMahon at 11:10, 31 March 2008

2008-03-31T11:10:27Z

New page

== Definition ==

A measure of the scattering power of an isolated atom. Also known as the '''atomic form factor'''. The scattering factor depends on the scattering amplitude of an individual atom and also the [[Bragg angle]] of scattering. It depends on the type of radiation involved.

== X-ray scattering ==

The scattering from a crystal of an X-ray beam results from the interaction between the electric component of the incident electromagnetic radiation and the electrons in the crystal. Tightly bound electrons scatter coherently (Rayleigh scattering); free electrons scatter incoherently (Compton scattering). The scattering process from atomic electrons in a crystal lattice has both coherent and incoherent components, and is described as Thomson scattering.

The scattering amplitude from a neutral atom depends on the number of electrons (''Z'' = the atomic number) and also on the [[Bragg angle]] θ – destructive interference among waves scattered from the individual electrons reduces the intensity at other than zero scattering angle. For θ = 0 the scattering amplitude is normally equal to ''Z''. However, the scattering factor is modified by [[anomalous scattering]] if the incident wavelength is near an absorption edge of the scattering element.

[[Category:Physical properties of crystals]]
[[Category:Structure determination]]
[[Category:X-rays]]

The X-ray scattering factor is evaluated as the Fourier transform of the electron density distribution of an atom or ion, which is calculated from theoretical wavefunctions for free atoms.

← Older revision		Revision as of 18:09, 8 November 2017
Line 1:		Line 1:
−	<~~Font~~ color="blue">Facteur de diffusion atomique</~~Font~~> (''Fr''). <~~Font~~ color="red">Formfaktor</~~Font~~> (''Ge''). <~~Font~~ color="~~green~~">~~Factor de forma atómica~~</~~Font~~> (''Sp''). <~~Font~~ color="~~black~~">~~Fattore di diffusione atomico~~</~~Font~~> (''It''). <~~Font~~ color="~~purple~~">~~原子散乱因子~~</~~Font~~> (''Ja'').	+	<font color="blue">Facteur de diffusion atomique</font> (''Fr''). <font color="red">Atomformfaktor, Formfaktor</font> (''Ge''). <font color="black">Fattore di diffusione atomico</font> (''It''). <font color="purple">原子散乱因子</font> (''Ja''). <font color="green">Factor de forma atómica</font> (''Sp'').

	== Definition ==		== Definition ==

@@ Line 1: / Line 1: @@
-<Font color="blue">Facteur de diffusion atomique</Font> (''Fr''); <Font color="red">Formfaktor</Font> (''Ge''); <Font color="green">Factor de forma atómica</Font> (''Sp''); <Font color="black">Fattore di diffusione atomico</Font> (''It''); <Font color="purple">原子散乱因子</Font> (''Ja'').
+<Font color="blue">Facteur de diffusion atomique</Font> (''Fr''). <Font color="red">Formfaktor</Font> (''Ge''). <Font color="green">Factor de forma atómica</Font> (''Sp''). <Font color="black">Fattore di diffusione atomico</Font> (''It''). <Font color="purple">原子散乱因子</Font> (''Ja'').
 == Definition ==
-A measure of the scattering power of an isolated atom. Also known as the '''atomic form factor'''. The scattering factor depends on the scattering amplitude of an individual atom and also the [[Bragg angle]] of scattering. It depends on the type of radiation involved.
+A measure of the scattering power of an isolated atom. Also known as the '''atomic form factor'''. The scattering factor depends on the scattering amplitude of an individual atom, on the [[Bragg angle]] and the type of radiation involved.
 == X-ray scattering ==

@@ Line 15: / Line 15: @@
 The X-ray scattering factor is evaluated as the Fourier transform of the electron density distribution of an atom or ion, which is calculated from theoretical wavefunctions for free atoms.
-== See also ==
+== References ==
-Electron diffraction.
+*''Electron diffraction'': C. Colliex, J. M. Cowley, S. L. Dudarev, M. Fink, J. Gjønnes, R. Hilderbrandt, A. Howie, D. F. Lynch, L. M. Peng, G. Ren, A. W. Ross, V. H. Smith Jr, J. C. H. Spence, J. W. Steeds, J. Wang, M. J. Whelan and B. B. Zvyagin. ''International Tables for Crystallography'' (2006). Vol. C, ch. 4.3, pp. 259-429  [http://dx.doi.org/10.1107/97809553602060000593 doi:10.1107/97809553602060000593]
-C. Colliex, J. M. Cowley, S. L. Dudarev, M. Fink, J. Gjønnes, R. Hilderbrandt, A. Howie, D. F. Lynch, L. M. Peng, G. Ren, A. W. Ross, V. H. Smith Jr, J. C. H. Spence, J. W. Steeds, J. Wang, M. J. Whelan and B. B. Zvyagin. ''International Tables for Crystallography'' (2006). Vol. C, ch. 4.3, pp. 259-429  [http://dx.doi.org/10.1107/97809553602060000593 doi:10.1107/97809553602060000593]
+*''Intensity of diffracted intensities'': P. J. Brown, A. G. Fox, E. N. Maslen, M. A. O'Keefe and B. T. M. Willis. ''International Tables for Crystallography'' (2006). Vol. C, ch. 6.1, pp. 554-595  [http://dx.doi.org/10.1107/97809553602060000600 doi:10.1107/97809553602060000600]
+*''Neutron techniques'': I. S. Anderson, P. J. Brown, J. M. Carpenter, G. Lander, R. Pynn, J. M. Rowe, O. Schärpf, V. F. Sears and B. T. M. Willis. ''International Tables for Crystallography'' (2006). Vol. C, ch. 4.4, pp. 430-487  [http://dx.doi.org/10.1107/97809553602060000594 doi:10.1107/97809553602060000594]

← Older revision		Revision as of 11:46, 14 April 2016
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−	<Font color="blue">Facteur de ~~structure~~ atomique </Font>(''Fr'').	+	<Font color="blue">Facteur de diffusion atomique</Font> (''Fr''); <Font color="red">Formfaktor</Font> (''Ge''); <Font color="green">Factor de forma atómica</Font> (''Sp''); <Font color="black">Fattore di diffusione atomico</Font> (''It''); <Font color="purple">原子散乱因子</Font> (''Ja'').

	== Definition ==		== Definition ==

@@ Line 12: / Line 12: @@
 The scattering amplitude from a neutral atom depends on the number of electrons (''Z'' = the atomic number) and also on the [[Bragg angle]] &theta; &ndash; destructive interference among waves scattered from the individual electrons reduces the intensity at other than zero scattering angle. For &theta; = 0 the scattering amplitude is normally equal to ''Z''. However, the scattering factor is modified by [[anomalous scattering]] if the incident wavelength is near an absorption edge of the scattering element.
 The X-ray scattering factor is evaluated as the Fourier transform of the electron density distribution of an atom or ion, which is calculated from theoretical wavefunctions for free atoms.
@@ Line 29: / Line 25: @@
 Neutron techniques.
 I. S. Anderson, P. J. Brown, J. M. Carpenter, G. Lander, R. Pynn, J. M. Rowe, O. Schärpf, V. F. Sears and B. T. M. Willis. ''International Tables for Crystallography'' (2006). Vol. C, ch. 4.4, pp. 430-487  [http://dx.doi.org/10.1107/97809553602060000594 doi:10.1107/97809553602060000594]

← Older revision		Revision as of 12:12, 1 April 2008
Line 8:		Line 8:

	The scattering from a crystal of an X-ray beam results from the interaction between the electric component of the incident electromagnetic radiation and the electrons in the crystal. Tightly bound electrons scatter coherently (Rayleigh scattering); free electrons scatter incoherently (Compton scattering). The scattering process from atomic electrons in a crystal lattice has both coherent and incoherent components, and is described as Thomson scattering.		The scattering from a crystal of an X-ray beam results from the interaction between the electric component of the incident electromagnetic radiation and the electrons in the crystal. Tightly bound electrons scatter coherently (Rayleigh scattering); free electrons scatter incoherently (Compton scattering). The scattering process from atomic electrons in a crystal lattice has both coherent and incoherent components, and is described as Thomson scattering.
		+
		+	[[Image:scatfacs.gif\|frame\|Scattering factor of stationary C and Fe atoms plotted as a function of Bragg angle for incident X-ray wavelength of 0.70930 Å. Ticks on the horizontal axis correspond to Bragg angle increments of 10 degrees; ticks on the vertical axis are increments of 5 electrons.\|right]]

	The scattering amplitude from a neutral atom depends on the number of electrons (''Z'' = the atomic number) and also on the [[Bragg angle]] θ – destructive interference among waves scattered from the individual electrons reduces the intensity at other than zero scattering angle. For θ = 0 the scattering amplitude is normally equal to ''Z''. However, the scattering factor is modified by [[anomalous scattering]] if the incident wavelength is near an absorption edge of the scattering element.		The scattering amplitude from a neutral atom depends on the number of electrons (''Z'' = the atomic number) and also on the [[Bragg angle]] θ – destructive interference among waves scattered from the individual electrons reduces the intensity at other than zero scattering angle. For θ = 0 the scattering amplitude is normally equal to ''Z''. However, the scattering factor is modified by [[anomalous scattering]] if the incident wavelength is near an absorption edge of the scattering element.

← Older revision		Revision as of 15:52, 31 March 2008
Line 1:		Line 1:
		+	<Font color="blue">Facteur de structure atomique </Font>(''Fr'').
		+
	== Definition ==		== Definition ==

← Older revision		Revision as of 11:40, 31 March 2008
Line 14:		Line 14:

	The X-ray scattering factor is evaluated as the Fourier transform of the electron density distribution of an atom or ion, which is calculated from theoretical wavefunctions for free atoms.		The X-ray scattering factor is evaluated as the Fourier transform of the electron density distribution of an atom or ion, which is calculated from theoretical wavefunctions for free atoms.
		+
		+	== See also ==
		+
		+	Electron diffraction.
		+	C. Colliex, J. M. Cowley, S. L. Dudarev, M. Fink, J. Gjønnes, R. Hilderbrandt, A. Howie, D. F. Lynch, L. M. Peng, G. Ren, A. W. Ross, V. H. Smith Jr, J. C. H. Spence, J. W. Steeds, J. Wang, M. J. Whelan and B. B. Zvyagin. ''International Tables for Crystallography'' (2006). Vol. C, ch. 4.3, pp. 259-429 [http://dx.doi.org/10.1107/97809553602060000593 doi:10.1107/97809553602060000593]
		+
		+	Intensity of diffracted intensities.
		+	P. J. Brown, A. G. Fox, E. N. Maslen, M. A. O'Keefe and B. T. M. Willis. ''International Tables for Crystallography'' (2006). Vol. C, ch. 6.1, pp. 554-595 [http://dx.doi.org/10.1107/97809553602060000600 doi:10.1107/97809553602060000600]
		+
		+	Neutron techniques.
		+	I. S. Anderson, P. J. Brown, J. M. Carpenter, G. Lander, R. Pynn, J. M. Rowe, O. Schärpf, V. F. Sears and B. T. M. Willis. ''International Tables for Crystallography'' (2006). Vol. C, ch. 4.4, pp. 430-487 [http://dx.doi.org/10.1107/97809553602060000594 doi:10.1107/97809553602060000594]