Alternative charge-order polymorph for half-doped manganites in TbBaMn2O6 -: art. no. 220405

The half-doped manganite perovskite TbBaMn2O6 (Tb0.5Ba0.5MnO3) has been prepared by low-temperature oxygen intercalation into TbBaMn2O5. Neutron powder diffraction shows that at 300 K, TbBaMn2O6 has a triclinic distorted perovskite superstructure exhibiting long-range order of the Tb3+ and Ba2+ cations, displacements of the intercalated oxygens, Mn3+ and Mn4+ charge states, and Mn3+ orbital states. The "rocksalt" charge order is different from the "striped" arrangement found in many other half-doped manganite perovskites such as (La0.5Ca0.5)MnO3, demonstrating that internal strains induced by the cations can lead to polymorphism of charge ordering in a transition-metal oxide framework.