Abstract
We report discovery of collinear-magnetism-driven ferroelectricity in the Ising chain magnet (). Neutron diffraction shows that and ions alternating along the chains exhibit an up-up-down-down () magnetic order. The ferroelectricity results from the inversion symmetry breaking in the spin chain with an alternating charge order. Unlike in spiral magnetoelectrics where antisymmetric exchange coupling is active, the symmetry breaking in occurs through exchange striction associated with symmetric superexchange.
- Received 13 September 2007
DOI:https://doi.org/10.1103/PhysRevLett.100.047601
©2008 American Physical Society