The magnetic structure of the compound Ho5Sb3

We have investigated the magnetic behavior of Ho5Sb3 compound (Mn5Si3-type, hexagonal; a=0.8865(1) nm, c=0.6232(1) nm, as derived from X-ray Guinier powder pattern) by using the techniques of magnetization, electrical resistivity, heat capacity and neutron diffraction. We find that Ho5Sb3 exhibits a ferrimagnetic type (Ferrimagnet I) ordering below 60 K with propagation vectors K0=[0, 0, 1] and K1=[±Kx, 0, 0]. Below 40 K, the thermal variation of magnetic reflections and the appearance of an additional magnetic component with propagation vector K2=[0, 1/2, 0] show the onset of an antiferromagnetic type of ordering in the magnetic structure; which evolves into yet another ferrimagnetic structure (Ferrimagnet II) as the temperature is lowered down to 2 K. The magnetic moments of the Ho atoms at the (4d) and (6g) sites with magnitudes of nearly 7.4 and 6.3 μB at 2 K, respectively, are inclined approximately at 70° to the c-axis.