Magnetic structure of rare earth intermetallic compound Er6MnTe2: Neutron diffraction and magnetization study

Magnetic properties of polycrystalline Er6MnTe2 compound of hexagonal structure (Fe2P-type, non-centrosymmetric space group P-62m, no. 189, hP9) has been studied using dc magnetization measurements and powder neutron diffraction. The compound Er6MnTe2 orders ferromagnetically at 76 K (TC) and undergoes another transition at ∼10 K (Tm) within the ordered state. Magnetization shows a tendency to saturate at 2 K in fields of 70 kOe to 9.8 μB/Er3+. In the neutron diffraction data, commensurate magnetic reflections are present in the temperature range of 68 K to 48 K indicating collinear ferromagnetic ordering of Er sublattice with propagation vector (k0 = [0, 0, 0]). A non-collinear ferromagnetic ordering with moments in ab-plane is observed from about 38 K to 8 K. At TC, the moments at two Er sites (3f and 3g) are different whereas below Tm (i.e., at 8 K), both Er moments approach value of about 9 μB.