We have confirmed by neutron diffraction that the high-temperature phase of
TbRu2Si2, exhibits a magnetic one-dimensional modulation with Q = (3/13 0
0), while for the intermediate phase the modulation becomes two-dimensional
with many satellites. At low-temperature the magnetic structure changes to
another two-dimensional one. (C) 2000 Elsevier Science B.V. All rights res
erved.