Structural and physical properties of Lu2Fe4O9 and Lu2Fe2Mn2O9

The structural and physical properties of layered Lu2Fe4O9 and Lu2Fe2Mn2O9 have been extensively investigated. The atomic parameters of Lu2Fe4O9 have been determined and transmission electron microscopy (TEM) observations demonstrate that Lu2Fe4O9, arising from the introduction of additional O atoms in LuFe2O4, has an evidently different average structure in comparison with LuFe2O4. Lu2Fe4O9 in general shows up complex superstructures in connection with the introduced oxygen atoms and the resultant structural distortions. Complex superstructures of Lu2Fe2Mn2O9 were also investigated by TEM, to be compared with that of Lu2Fe4O9. High-resolution TEM investigations also reveal a rich variety of microstructure phenomena with visible local structural inhomogeneity in both Lu2Fe4O9 and Lu2Fe2Mn2O9. Experimental measurements of physical properties suggest that the additional oxygen could result in visible changes of the electric, magnetic, and dielectric properties in the Lu–Fe–O materials. Experimental measurements also reveal that partial substitution of Mn for Fe in Lu2Fe4O9 could evidently influence the physical properties.