Figure 3
Energy versus polar mode [ OP(0,h,0)] magnitude for AFM [mX3+ mX1- OP(a,0,0d,0,0)] and FM () ordering. The inset illustrates the linear behaviour around the origin. The amplitude of the mode is determined by summing the displacements of all the atoms in the unit cell and presented as a percentage with respect to the ground-state amplitude of the AFM phase. In both AFM and FM phases the energy shown is with respect to the structure with zero magnitude of . |