Field dependence of the incommensurate magnetic order in UNiGe

Abstract Between 42 and 50 K, UNiGe exhibits an incommensurate phase (IP) with q =(0, δ, δ) with a δ that is slightly larger than 1 3 in zero field. We have studied the field dependence of this magnetic structure by means of neutron diffraction on single-crystalline UNiGe. It has been found that δ increases almost linearly with decreasing temperature at fixed fields, while it is only weakly field dependent at fixed temperatures. The results favor the interpretation of the IP in terms of moment modulation instead of the previously proposed spin-slip phase.