POSSIBILITY OF OBSERVATION OF NONTRIVIAL MAGNETIC ORDER BY ELASTIC NEUTRON-SCATTERING IN MAGNETIC-FIELD

We consider the neutron scattering in the magnetic phases with zero average sublattice magnetization (double- or triple-spin correlator as an order parameter). External magnetic field induces different magnetizations on the different sublattices in such a system. As a result, the new purely magnetic Bragg peaks for the elastic neutron scattering appear. We present the estimates of intensities in the Bragg peaks and their angular dependence on the external magnetic field. This could serve as a test whether the nontrivial magnetic order exists in some heavy fermion compounds, like URu2Si2 or UPt3 and possibly in the high-T(c) oxides.