Synthesis, structural, and magnetic characterization of YCrMnO5

A new oxide of nominal stoichiometry YCrMnO5 has been prepared in polycrystalline form by wet-chemistry procedures followed by thermal treatments under high-oxygen-pressure conditions. This material has been characterized by X-ray and neutron powder diffraction (NPD), magnetotransport and magnetization measurements. YCrMnO5 is iso-structural with RMn2O5 oxides (R = rare earths); its crystal structure has been Rietveld refined from NPD data in the space group Pbam, and it contains infinite chains of (Cr,Mn)O-4+(6) octahedra sharing edges, linked together by (Mn,Cr)O-5 pyramids and YO8 units. An important level of cationic disorder has been found between both metallic sites;the refined crystallographic formula is Y[Mn0.47(1)Cr0.53 (1)]oct[Cr0.37(1)Mn0.63(1)]pyrO(5). The magnetic susceptibility indicates the onset of magnetic ordering below T-c approximate to 85 K; the magnetization isotherms are characteristic of a weakly ferrimagnetic material reaching a net magnetization of 0.25 mu(B)/f.u. for H = 50 kOe. Low-temperature NPD patterns do not exhibit any additional magnetic contribution, confirming that a long-range magnetic ordering is not fully established.