NEUTRON DIFFRACTION STUDY OF THE MAGNETIC ORDERING IN GdBa2Cu3O7-δ T. Chattopadhyay, H. Maletta, W. Wirges, K. Fischer et P. J. Brown J. Phys. Colloques, 49 C8 (1988) C8-2171-C8-2172 DOI: 10.1051/jphyscol:19888973