Analogies and differences between ferroelectrics and ferromagnets

Abstract

We describe the similarities and differences between ferromagnets - materials that have a spontaneous magnetization that is switchable by an applied magnetic field - and ferroelectrics, which have an analogous electric-field switchable electric polarization. After comparing the driving force for ion off-centering that causes the polarization in ferroelectrics with the physics of spin polarization that causes the magnetization of ferromagnets, we analyze the mechanisms of domain formation and resulting domain structures in both material classes. We describe the emerging technologies of ferroelectric and magnetoresistive random access memories, and discuss the behavior of magnetoelecric multiferroics, which combine ferromagnetism and ferroelectricity in the same phase. © 2007 Springer-Verlag Berlin/Heidelberg.