Magnetic properties of NdxEr_1-xMn₆Sn ₆alloys

We have conducted low- and high-field magnetization measurements and neutron diffraction experiments on Nd_xEr_1-xMn ₆Sn₆ alloys (0 x 0.5) with hexagonal MgFe ₆Ge₆ type structure. The alloy with x 0.1 shows a complex helical antiferromagnetism with the magnetic moments rotating in the c plane below the Curie temperature T_C 340 K, and a ferrimagnetism below the temperature T_t 100 K. In the ferrimagnetic state, the magnetic moments μ_Mn and μ_Nd are parallel to each other, and antiparallel to μ_Er. The alloy with x 0.4 shows also a similar ferrimagnetic structure below the Curie temperature T_C 360 K. It is likely that the each magnetic moments are keep a constant values of μ_Mn 2.3 μ_B/Mn atom, μ_Nd 3 μ_B/Nd atom and μ_Er 9 μ_B/Nd atom at 10 K in the whole composition (0 < x 0.5). The ferrimagnetic arrangements for the alloys with 0.2 x 0.5 are not almost disturbed by magnetic field up to 26 T at 4.2 K.