Difference between revisions of "Guinier plot"

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(Rule of thumb)
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==Rule of thumb==
 
==Rule of thumb==
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The larger one's particles are, the smaller the minimum ''[[q]]'' must be. One also only expects the Guinier scaling to be maintained up to a certain maximum ''q'':
 
* For spherical particles, <math>\scriptstyle q_{\mathrm{max}} < 1.3 R_g </math>
 
* For spherical particles, <math>\scriptstyle q_{\mathrm{max}} < 1.3 R_g </math>
 
* For elongated particles, <math>\scriptstyle q_{\mathrm{max}} < 0.8 R_g </math>
 
* For elongated particles, <math>\scriptstyle q_{\mathrm{max}} < 0.8 R_g </math>

Revision as of 09:41, 25 July 2015

A Guinier analysis attempts to extract the size-scale for a structure by fitting the scattering to an equation of the form:

Thus a plot of ln(I) vs. q2 can be used to highly the scaling of the scattering. A straight-line in such a plot is indicative of Guinier scaling. Such an analysis is typically only done with the low-q portion of the data.

Rule of thumb

The larger one's particles are, the smaller the minimum q must be. One also only expects the Guinier scaling to be maintained up to a certain maximum q:

  • For spherical particles,
  • For elongated particles,

See Also