Layer lattice compounds electron diffraction

The powdered XRD pattern of the parent LiMnOj compound with simulated x-ray patterns of (a) layered LiMn02 (C2/m) and (b) lithiated-spinel Ll2(Mn2)04 (F4i/idm). (Reprinted with permission from Y. Shao-Hornet al. Thackeray, Structural characterization of layered LiMn02 electrodes by electron diffraction and lattice imaging, /. Electrochem. Soc. 146, 1999, 2404-2412. Copyright 1999. The Electrochemical Society.)... 

For the network of stoichiometry [Mn Fe (ox)3], one encounters the rare situation of a bimetallic lattice in which both metal ions have the same electronic ground state, namely 3i/ , S = 5/2, T i. In this case, the compound has been found to mimic antiferromagnetic behavior. Thus the temperature dependence of the magnetic susceptibility is that of a classic two-dimensional antiferro-magnet, reaching a broad maximum at 55 K. Definitive evidence for this behavior comes from a neutron powder diffraction study, which revealed a simple collinear antiferromagnetic alignment of Mn and Fe moments parallel to the c-axis, or in other words perpendicular to the layers. 

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