2009/06/02 by Kunihiko Yamauchi, Tetsuya Fukushima, Silvia Picozzi · 3 citations
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Charge (physics) #Charge ordering #Chemistry #Condensed matter physics #Crystal structure #Crystallography #Dielectric #Dipole #Ferroelectricity #Magnetic Properties and Synthesis of Ferrites #Materials science #Monoclinic crystal system #Multiferroics #Multiferroics and related materials #Octahedron #Physical chemistry #Physics #Polarization (electrochemistry) #Quantum mechanics #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.79.212404
5 pages, 4 figures, accepted for publication in Phys. Rev. B
arxiv created 2009/06/02 · openalex publication_date 2009/06/18 · arxiv updated 2015/05/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
By means of first-principles simulations, we unambiguously show that improper ferroelectricity in magnetite in the low-temperature insulating phase is driven by charge-ordering. An accurate comparison between monoclinic ferroelectric Cc and paraelectric P2/c structures shows that the polarization arises because of ``shifts'' of electronic charge between octahedral Fe sites, leading to a noncentrosymmetric Fe2+/Fe3+ charge-ordered pattern. Our predicted values for polarization, in good agreement with available experimental values, are discussed in terms of point-charge dipoles located on selected Fe tetrahedra, pointing to a manifest example of electronic ferroelectricity driven by charge rearrangement.