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 60K with propagation vectors K-0 [ 0, 0, 1] and K-1 [+/- K-x, 0, 0]. Below 40 K, the thermal variation of magnetic reflections and the appearance of an additional magnetic component with propagation vector K-2 [ 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 2K. The magnetic moments of the Ho atoms at the (4d) and (6g) sites with magnitudes of nearly 7.4 and 6.3 mu(B) at 2K, respectively, are inclined approximately at 701 to the c-axis. (c) 2008 Elsevier B.V. All rights reserved.