A variable field neutron diffraction study of the ruthenocuprate RuSr2Nd0.9Y0.2Ce0.9Cu2O10-delta, which exhibits large negative magnetoresistance, has been performed in order to determine the variation of the magnetic structure with magnetic field. Upon application of a magnetic field the (1/21/21/2) and (1/21/2l) magnetic peaks reduce in intensity as the spins in the RuO2 and CuO2 layer cant into a ferromagnetic alignment in the ab- plane. This results in increased spin polarised transport in the CuO2 plane and hence large negative magnetoresistance. (c) 2006 Elsevier B.V. All rights reserved.
- canted antiferromagnet