Magnetic structures of Er5Rh4Ge10 compound

A powder neutron diffraction measurement of Er5Rh4Ge10 is reported. This compound crystallizes in the tetragonal Sc5Co4Si10-type structure (space group P4/mbm) in which the Er atoms occupy three different sites. The neutron diffraction measurements indicate antiferromagnetic order with the Néel temperature TN=5.5 K. Below TN an additional phase transition connected with the change of the magnetic structure is observed at 4.3 K. At low temperatures the Er moments form a sine-wave modulated structure with the propagation vector k=(¼, ¼, 0) for 1.5 K<T<4.2 K and (⅓, ⅓, 0) for 4.2 K up to TN. The values of the magnetic moments are different in the different sublattices and all are parallel to the c-axis. Determined magnetic structures are compared to the results from symmetry analysis. - Highlights: ► Er5Rh4Ge10 compound is antiferromagnet with the Néel temperature 5.5 K. ► Er moments from a sine-wave modulated structure with the propagation vector k=(kx, ky, 0). ► At T=4.2 K the change of the kx component from ¼ for 1.5 K<T<4.2 K to ⅓ for 4.2 K up to TN is observed. ► The magnetic moments are different in three different sublattices and are parallel to the c-axis. ► Determined magnetic structures are in good agreement with the results of symmetry analysis