The recent research on multiferroics has provided solid evidence that the breaking of inversion symmetry by spin order can induce ferroelectric polarization P. This type of multiferroics, called spin-driven ferroelectrics, often show a gigantic change in P on application of a magnetic field B. However, their polarization (<∼0.1 μC cm -2) is much smaller than that in conventional ferroelectrics (typically several to several tens of μC cm -2). Here we show that the application of external pressure to a representative spin-driven ferroelectric, TbMnO 3, causes a flop of P and leads to the highest P (≈1.0 μC cm -2) among spin-driven ferroelectrics ever reported. We explain this behaviour in terms of a pressure-induced magnetoelectric phase transition, based on the results of density functional simulations. In the high-pressure phase, the application of B further enhances P over 1.8 μC cm -2. This value is nearly an order of magnitude larger than those ever reported in spin-driven ferroelectrics.
ASJC Scopus subject areas
- 化学 (全般)