Magnetic structures of the metal monoxides NiO and CoO re-investigated by spherical neutron polarimetry

The metal monoxides NiO and CoO both order antiferromagnetically. In NiO, the moments are perpendicular to the propagation vector. In the case of CoO, some discrepancies exist as far as the direction of the moments is concerned. We have taken advantage of the high sensitivity of the spherical neutron polarimetry as implemented in CRYOgenic Polarization Analysis Device (CRYOPAD) to reinvestigate their magnetic structures. The results of these experiments are presented and discussed. (c) 2006 Elsevier B.V. All rights reserved.