Neutron-diffraction study of quadrupolar and magnetic order in TmTe.

Abstract

Neutron-diffraction measurements on the quadrupolar and magnetic-ordered phases of TmTe are reviewed. By carefully analyzing the magnetic dipole structure induced by an external magnetic field applied along the main symmetry directions, it is possible to determine the nature of the quadrupole order parameter. The data agree qualitatively with the results of a recent mean-field model. In particular. the prediction of an extra ferromagnetic component appearing below the Nt ei temperature, due to the preexisting quadrupole order, is confirmed experimentally. Form-factor measurements using polarized neutrons are also reported, (C) 2000 Elsevier Science B.V. All rights reserved.