Magnetic structures of R2RhSi3 (R=Ho, Er) compounds

Powder X-ray and neutron diffraction and magnetic measurements have been performed on R2RhSi3 (R=Ho and Er) compounds at low temperatures. The compounds crystallize in a derivative of the hexagonal AlB2-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 Neel temperatures of 5.2 K for Ho2RhSi3 and 5 K for Er2RhSi3. Both compounds exhibit collinear magnetic structures, described by the propagation vector k = (1/2,0,0) for Ho2RhSi3 and k = (0,0,0) for Er2RhSi3. This magnetic order is stable in the temperature range between 1.5 K and the Neel temperature. (C) 2003 Elsevier B.V. All rights reserved.