Synthesis, structure and physical properties of Ru ferrites:: BaMRu5O11 (M = Li and Cu) and BaM′2Ru4O11 (M′ = Mu, Fe and Co)

The synthesis, structure, and physical properties of five R-type Ru ferrites with chemical formula BaMRu5O11 (M = Li and Cu) and BaM'2Ru4O11 (M = Mn, Fe and Co) are reported. All the ferrites crystallize in space group P6(3)/mmc and consist of layers of edge sharing octahedra interconnected by pairs of face sharing octahedra and isolated trigonal bipyramids. For M = Li and Cu, the ferrites are paramagnetic metals with the M atoms found on the trigonal bipyramid sites exclusively. For M' = Mn, Fe and Co, the ferrites are soft ferromagnetic metals. For M' = Mn, the Mn atoms are mixed randomly with Ru atoms on different sites. The magnetic structure for BaMn2Ru4O11 is reported. (C) 2005 Elsevier Inc. All rights reserved.