Antiferromagnetic order in TbFe2Al10 and DyFe2Al10

The magnetic properties of the orthorhombic aluminides TbFe2Al10, DyFe2Al10 and HoFe2Al10 have been investigated by neutron powder diffraction. Below the Neel temperatures T-N = 16.5(5) and T-N = 7.5(5)K the terbium and dyspr osium moments show incommensurate magnetic order with the wave vectors k = (0, 0.7977, 0) and k = (0, 0.7836, 0), respectively. TbFe2Al10 shows a squa re wave modulated magnetic ordering of the terbium sublattice with a moment direction parallel to the a-axis. In DyFe2Al10 the dysprosium moments rota te within the nc-plane forming a helical. magnetic structure. For HoFe2Al10 no magnetic order could be observed down to 1.5 K. (C) 2000 Elsevier Scien ce B.V. All rights reserved.