Antiferromagnetic properties of ternary galides RRhGa (R=Tb, Ho and Er)

Abstract Neutron diffraction and magnetic measurements have been performed on RRhGa (R=Tb, Ho and Er) series of compounds at low temperatures. The compounds crystallize in the orthorhombic TiNiSi-type structure (space group Pnma). The crystal structure parameters have been refined on the basis of neutron diffraction patterns collected in the paramagnetic region. These compounds are antiferromagnets with the Neel temperature equal to 22 K for TbRhGa, 4.6 K for HoRhGa and 4.5 K for ErRhGa. All compounds exhibit a collinear magnetic structure described by the propagation vector k =(0, 1 2 ,0) . This order is stable in the temperature range between 1.5 K and Neel temperature.