The magnetic ordering in the Ho6FeTe2 compound

The magnetic structure of the ternary intermetallic compound Ho6FeTe2 (hexagonal Zr6CoAs2 structure type, a ternary ordered variant of the Fe2P-type; space group P6¯2m, No 189) has been investigated by neutron diffraction and magnetization measurements.The neutron diffraction study shows that in between the temperatures TN ∼ 24 K and TC ∼ 8 K the magnetic moments of the Ho atoms adopt a flat helix ordering with elliptical envelope having a wave vector K = [0, 0, ∼1/9], the helix axis being coincident with the c  -axis (with maximal magnetic moments of MHo1=6.5(7) μBMHo1=6.5(7) μB and MHo2=8.0(7) μB,MHo2=8.0(7) μB, at 10 K). Below the TC ∼ 8 K the magnetic structure of Ho6FeTe2 changes to a ferromagnetic cone: superposed on the helix ordering within the basal plane a ferromagnetic ordering with K = [0, 0, 0] and moments pointing in the c-direction appears. At 2 K the total maximal magnetic moments amount to MHo1=9.1(7) μBMHo1=9.1(7) μB and MHo2=9.6(7) μBMHo2=9.6(7) μB with a ferromagnetic component on the Ho1Ho1 site of McHo1=2.2(5) μBMcHo1=2.2(5) μB and on the HO2HO2 site of McHo2=5.2(5) μB.McHo2=5.2(5) μB. No local moment was detected on the iron atomic site in this compound.Magnetization measurements confirm the first magnetic transition at ∼26 K and the second at ∼10 K. The magnetization vs. field data obtained at 2.5 K show soft ferromagnetic behavior, with a saturation magnetization of 7.9 μB/Ho3+.