The multiferroic phase of DyFeO₃: an<i>ab initio</i>study

By performing accurate ab initio density functional theory (DFT) calculations, we study the role of 4f electrons in stabilizing the magnetic-field-induced ferroelectric state of DyFeO3. We confirm that the ferroelectric polarization is driven by an exchange-strictive mechanism, working between adjacent spin-polarized Fe and Dy layers, as suggested by Y Tokunaga (2008 Phys. Rev. Lett. 101 097205). A careful electronic structure analysis suggests that coupling between Dy and Fe spin sublattices is mediated by Dy–d and O–2p hybridization. Our results are robust with respect to the different computational schemes used for d and f localized states, such as the DFT+U method, the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional and the GW approach. Our findings indicate that the interaction between the f and d sublattices might be used to tailor the ferroelectric and magnetic properties of multiferroic compounds.