Switching the ferroelectric polarization in theS=1∕2chain cuprateLiCuVO4by external magnetic fields

摘要: We present a detailed study of the complex dielectric constant and ferroelectric polarization in multiferroic $\mathrm{Li}\mathrm{Cu}\mathrm{V}{\mathrm{O}}_{4}$ as function temperature external magnetic field. In zero field, spiral spin order with an $\mathbf{a}\mathbf{b}$ helix propagation vector along crystallographic $\mathbf{b}$ direction is established, which induces spontaneous parallel to $\mathbf{a}$. The can be reoriented by field allows switching polarization. find strong dependence absolute value for different orientations plane. Above $7.5\phantom{\rule{0.3em}{0ex}}\mathrm{T}$, reveals collinear remains paraelectric all directions. Thus, this system ideally suited check symmetry relations magnets predicted theoretically. coupling documented $(H,T)$ phase diagram fully explored.