Resonant scattering and multiple Bragg X-ray diffraction in LaMnO3; a classical view
Published in:
Acta Crystallographica Section A 62,(2006) 459-462;
Link to original published article:
http://dx.doi.org/doi:10.1107/S010876730603889X
Abstract
The mechanism for resonant scattering in LaMnO3 has been the subject of some controversy between two models. Model (A) is based on orbital ordering, whereas model (B) invokes the Jahn-Teller distortion. From the structural point of view, the two models lead to different d-electron densities. The forbidden reflection 300 is turned on by resonance, leading to a well defined scheme for the lobes of the Mn d electrons [ model (A)]. It turns out that the same experimental results could have been interpreted according to model (B). The only difference is that this alternative interpretation would have required a structure factor F-300 of opposite sign. This is a typical example of a phase problem. An experimental technique has been applied for phase determination based on multiple Bragg scattering. This shows that the multiple-beam results are in agreement with model (B), not with model (A), laying to rest a long overdue controversy.
Keywords
phase problem
Date of this Version
January 2006