Evidence of 4-q magnetic structure in TmS

Neutron magnetic diffraction experiments have been performed on single crystal TmS at 1.3 K and in applied magnetic fields up to 80 kOe to test the assumption of a mono-q structure which was made earlier. At low fields, variations of intensities associated with the 24 vectors of the star {q} clearly indicate that the magnetic structure in TmS is described by a coupling between 4 different Fourier components mq of the magnetic moments. Above 20 kOw a new antiferromagnetic structure in TmS has been observed for particular directions of the applied magnetic field. © 1986.