Simultaneous presence of two different magnetic structures in a single-crystalline solid? Hydrogen-distribution-dependent magnetism.

Abstract

In terms of density functional theory calculations, we explored the reason why the neutron diffraction patterns of a crystalline solid, NaFe2(H3O2)(MoO4)2, are explained by invoking the simultaneous presence of two widely different magnetic structures. The partitioning into OH and H2O groups of the "H3O2" units, which interconnect FeO4 chains in each [Fe2(H3O2)(MoO4)2](-) layer, leads to various layers different only in their H-atom positions. The crystal structure containing only symmetric FeO2(HO)(H2O) chains and that containing only asymmetric FeO4 chains are found to be responsible for the two observed magnetic structures.