Figure 4: Stabilization of the collinear E-AFM phase by applying pressure.
From: Giant spin-driven ferroelectric polarization in TbMnO3 under high pressure
(a) DFT-calculated total energy of different magnetic phases with respect to the FM phase, taking into account spin–orbit coupling. Calculated polarization along the a axis in the E-AFM configuration is also shown. (b) Superexchange energies (Jij): in-plane nearest-neighbour (J1), in-plane next-nearest-neighbour (J2), inter-plane nearest-neighbour (J′) and inter-plane next-nearest-neighbour (J′′). Negative (positive) values favour parallel (antiparallel) spin coupling. (c) Total energy versus orientation of the central Mn spins along an adiabatic polarization-switching path, connecting E1-AFM (P>0, φ=−90°), 90° spiral (P=0, φ=0°), and E2-AFM (P<0, φ=90°) phases.
