Magnetic structures of R 2RhSi 3 (R=Ho, Er) compounds

Abstract

Powder X-ray and neutron diffraction and magnetic measurements have been performed on R 2RhSi 3 (R=Ho and Er) compounds at low temperatures. The compounds crystallize in a derivative of the hexagonal AlB 2-type structure. The crystal structure parameters have been refined on the basis of the X-ray and neutron diffraction patterns collected in the paramagnetic region. These compounds are antiferromagnets with Néel temperatures of 5.2 K for Ho 2RhSi 3 and 5 K for Er 2RhSi 3. Both compounds exhibit collinear magnetic structures, described by the propagation vector k=(1/2,0,0) for Ho 2RhSi 3 and k=(0,0,0) for Er 2RhSi 3. This magnetic order is stable in the temperature range between 1.5 K and the Néel temperature.