Magnetic structures of the TbCuSb2 compound

Results of neutron diffraction measurements carried out for the TbCuSb2 com pound are reported. This compound crystallizes in the tetragonal ZrCuSi2-ty pe crystal structure and is an antiferromagnet below 9 K. The magnetic orde r at T=1.4 K is collinear, described by the propagation vector k=(1/2, 0, 0 ). With an increasing temperature, near T-t=5 K the magnetic structure chan ges to a collinear one with k=(0, 1/4, 1/2). Near the temperature of the ph ase transition, T(t)approximate to5 K the new phase which is probably sine wave modulated described by the propagation vector k=(0.423(1), 0, 0). (C) 2001 Elsevier Science B.V. All rights reserved.