Relative orientation of the magnetic moments in modulated multiferroic CaMn(7)O(12)

The modulated magnetic ordering in the multiferroic manganite CaMn(7)O(12) has been studied by using the neutron powder diffraction technique. The relative orientation of the magnetic moments of Mn4+ and Mn3+ ions located in Mn3 sublattice at (0,0,1/2) and Mn2 sublattice at (1/2,0,1/2) is shown to be antiparallel, i.e. their relative orientation angle Phi = n. This result differs from that given by other authors who propose another relative orientation with a value of Phi = 0.84(4) pi . The relative orientation angle is an important parameter used in model studies based on effective hamiltonians.