Magnetic properties of RPdGa (R=Gd–Er) compounds

Abstract

Lanthanide palladium gallides RPdGa (R=Gd–Er) show the orthorhombic, TiNiSi-type crystal structure. Magnetometric and neutron diffraction studies reveal that three of the title compounds are antiferromagnetic at low temperatures. TbPdGa exhibits, at 1.5 K, a complicated magnetic structure, which at 26 K transformed into a sine-wave modulated ordering described by the wave vector k=(0,0.3982(2),0). The Néel point of TbPdGa is at 34 K. A collinear antiferromagnetic order characterized by the wave vector k= ( 1 2 , 1 2 ,0) observed at 1.5 K in HoPdGa transforms near the Néel point at 6.8 K into a sine-wave modulated one with the wave-vector k=(0.628(1),0.475(1),0). ErPdGa has also a collinear antiferromagnetic structure at 1.5 K but with the wave vector k= (0, 1 3 ,0) . Near the Néel point at 5 K it transforms into a sine-wave modulated structure described by the wave-vector k=(0,0.3804(4),0). The magnetization curve of DyPdGa shows that this compound is ferromagnetic up to the Curie point at 20 K while the magnetic data for GdPdGa indicate antiferromagnetic ordering below 5.1 K.