We present neutron diffraction measurements in TbPt1-xCux for x = 0, 0.2, 0
.4, 0.6 and 0.8 samples. TbPt shows a ferromagnetic non-collinear-CxFs stru
cture. The Cu substitution modifies the conduction band inducing amplitude
modulated (AM) structures. For x = 0.2 and 0.4, these AM phases coexist wit
h the ferromagnetic ones while for x = 0.6 and 0.8 only AM structures are o
bserved. (C) 2000 Elsevier Science B.V. All rights reserved.