Magnetic properties of Fe2P-type Tb6FeTe2, Tb6CoTe2, Tb6NiTe2 and Er6FeTe2 compounds

The magnetic ordering of the Fe2P-type Tb6FeTe2, Tb6CoTe2 Tb6NiTe2 and Er6FeTe2 phases (space group P6¯2m) has been investigated through magnetization measurement and neutron powder diffraction. Tb6FeTe2, Tb6CoTe2 and Tb6NiTe2 demonstrate high-temperature ferromagnetic and low-temperature spin reorientation transitions, whereas Er6FeTe2 shows antiferromagnetic transition, only. The Tb6FeTe2 and Tb6NiTe2 phases show same high-temperature collinear ferromagnetic structure, whereas Tb6FeTe2 is the commensurate non-collinear ferromagnet and Tb6NiTe2 is the canted ferromagnetic cone with K1=[0, 0, ±3/10] and K2=[±2/9, ±2/9, 0] wave vectors at 2 K. The magnetic structure of Er6FeTe2 is a flat spiral with K1=[0, 0, ±1/10] at 2 K. The magnetic entropy change for Tb6NiTe2 is ΔSm=−4.86 J/kg K at 229 K for the field change Δμ0H=0–5 T. In addition, novel Fe2P-type Gd6FeTe2, Zr6FeTe2, Hf6FeTe2, Dy6NiTe2, Zr6NiTe2 and Hf6NiTe2 phases have been obtained.