Resonant scattering and multiple Bragg X-ray diffraction in LaMnO3; a classical view
The mechanism for resonant scattering in LaMnO
3 has been the subject of some controversy between two competing models, leading to different
d-electron densities. Forbidden reflections like 300 and 10-4 are turned on by resonance. Three-beam diffraction can be used to resolve ambiguities in determining valence electron densities obtained by means of resonant scattering. The choice between a negative and a positive structure factor is a particular aspect of the phase problem for which the technique of three-beam diffraction is particularly suited.
R. Colella and Q. Shen
![[resonant scattering]](https://www.iucr.org/__data/assets/image/0008/4031/dm0001.gif)
Intensity vs. azimuthal angle for the 10-4 in proximity of full excitation of the -1-20. The 10-4 Bragg reflection is centered at 148.4°. The asymmetry of the profile is clearly visible and is a phase effect, corresponding to a particular model for the charge density.
