Symmetry Origin of the Dzyaloshinskii-Moriya Interaction and Magnetization Reversal in YVO.

We have investigated magneto-structural phase transitions in polycrystalline YVO using high-resolution neutron powder diffraction toward understanding the phenomenon of magnetization reversal. Contrary to earlier reports, our study reveals that both C-type and G-type antiferromagnetic ordering, corresponding to G-type and C-type orbital ordered phases, respectively, occur at the same temperature ( = 115 K) with the G-type antiferromagnetic phase growing at the expense of the C-type one on cooling. These processes cease at ∼ 77 K; however, a minor (∼4%) untransformed C-type phase remains unchanged down to 1.7 K. The symmetry analysis indicates different symmetry origins of the Dzyaloshinskii-Moriya interaction in each phase, which can explain the magnetization reversal observed between and . We discuss that magnetic phase separation and associated weak ferromagnetism may be the common mechanism underlying the magnetization reversal phenomenon observed in other RVO systems (R = rare earth).