New ferromagnetic arsenides with complex magnetic structures

The recently synthesized family of rare-earth (R) manganese arsenide R2Mn2As3 (R = Pr, Sm, Ce and La) show promising magnetic properties. The magnetic members of the family (Pr, Sm, and Ce) show ferromagnetic transitions around 150 K, a substantially higher temperature compared to other ternary manganese arsenide families. The key feature of the magnetic behaviour may reside in the layered structures alternating loosely bound RAs and densely packed MnAs layers. Information on the electronic structure of R 4f and Mn 3d open shells and on the role of As in mediating the magnetic interaction is crucial to the understanding of their magnetism. HERFD XANES and RIXS measurements performed below and above the ordering temperature at the L3-edge of the R, the K-edge of Mn, and the K-edge of As will provide these information. Altogether, the proposed measurement campaign will set the bases for the understanding of the complex magnetic behaviour of the R2Mn2As3 family.