Magnetic ordering of TbNi3Ga2 studied by neutron diffraction and magnetic measurements

The magnetic and crystallographic properties of the compound TbNi3Ga2 have been studied by neutron diffraction and magnetic measurements. From magnetic measurements it is derived that TbNi3Ga2 orders ferromagnetically below about 14 K. Refinement of the neutron diffraction data obtained in the paramagnetic regime showed that TbNi3Ga2 adopts the hexagonal YCo3Ga2 type structure, but with a different distribution of the 3d atoms and Ga atoms over the three non-rare earth sites available in this structure type. Analysis of the neutron data obtained in the magnetically ordered regime shows that the magnetic structure is essentially ferromagnetic, the preferred direction of the Tb moments being perpendicular to the c direction. The Tb moment at the 2c site (3.9 mu(B)) is substantially lower than that at the 1a site (8.3 mu(B)).