An Introduction to Neutron Scattering - Spallation Neutron Source

Guinier Approximations: Analysis Road Map
* Viewgraph courtesy of Rex Hjelm
2
P(Q) =
d ln P(Q)
d ln(Q)
Generalized Guinier approximation
1; α = 0
απ Q –α ; α = 1,2 ΔM
2 2
α0 exp RαQ –
3 – α
Derivative-log analysis
= Q
P(Q)
d P(Q)
dQ
= –α –
2
3 – α R α 2 Q 2
• Guinier approximations provide a
roadmap for analysis.
• Information on particle
composition, shape and size.
• Generalization allows for
analysis of complex mixtures,
allowing identification of domains
where each approximation
applies.