Synthesis and study of the crystallographic and magnetic structure of DyFeMnO5: A new ferrimagnetic oxide

The title oxide has been obtained by replacing Mn3+ by Fe3+ in the parent oxide DyMn2O5. The crystallographic and magnetic structures have been analysed from neutron powder diffraction (NPD) data, in complement with susceptibility and magnetic measurements. DyFeMnO5 is orthorhombic, belonging to the Pbam space group as the parent compound. The crystal structure contains infinite chains of edge-sharing Mn4+O6 octahedra, interconnected by dimer units of Fe3+O5 square pyramids. There is a certain antisite disorder in the crystal structure, with 8.0% of the Mn4+ sites occupied by Fe cations, and 8.2% of the Fe3+ positions occupied by Mn3+ cations. The magnetization measurements show that DyFeMnO5 presents magnetic order below TC≈178 K; a study of the magnetic structure from the low-temperature NPD patterns indicates an antiferromagnetic coupling of the Mn4+ and Fe3+ spins, with the polarization of the Dy3+ magnetic moments parallel to the those of the Fe sublattice.