The two B-site ions Mn3+ and Mn4+ in the stoichiometric spinel structure LiMn2O4 form a complex, columnar ordered pattern below the charge-ordering transition at room temperature. On further cooling to below 66 K, the system develops long-range antiferromagnetic order. In contrast, whereas lithium-substituted Li[Mn2−xLix]O4 also undergoes a charge-ordering transition around room temperature, it only displays frozen in short-range magnetic order below ~25-30 K. We investigate to what extent the columnar charge-order pattern observed in LiMn2O4 can account for the measured magnetic ordering patterns in both the pure and Li-substituted (x=0.04) compounds. We conclude that eightfold rings of Mn4+ ions form the main magnetic unit in both compounds (x=0,0.04), and that clusters formed out of these rings act as superspins in the doped compound.
J. Gaddy et al., "Magnetic Ordering in the Spinel Compound Li[Mn2-xLix]O₄(X=0, 0.04)," Journal of Applied Physics, American Institute of Physics (AIP), Mar 2009.
The definitive version is available at http://dx.doi.org/10.1063/1.3073660
United States. Department of Energy
Keywords and Phrases
Antiferromagnetic Materials; Lithium Compounds; Long-Range Order; Magnetic Structure; Short-Range Order
Article - Journal
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