CRYSTAL AND MAGNETIC-STRUCTURE OF TBCO3GA2

Neutron diffraction on powdered sample was used to establish the cryst al and magnetic structure of TbCo3Ga2. This compound crystallizes in t he hexagonal structure which belongs to the P6/mmm space group. One of the five sites of its unit cell is equally occupied by Co and Ga atom s. The magnetic structure at 4 K is collinear ferrimagnetic with the m agnetic moment of terbium and cobalt sublattice in opposite directions , perpendicular to the c-axis. A transition around 30 K, presented in the magnetization vs. temperature curve is associated with a spin reor ientation. (C) 1997 Elsevier Science S.A.