By performing accurate ab-initio density functional theory 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 [Phys. Rev. Lett, \textbf{101}, 097205 (2008)]. 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 sublattice might be used to tailor ferroelectric and magnetic properties of multiferroic compounds.
@article{arxiv.0912.3345,
title = {The multiferroic phase of DyFeO$_{3}$:an ab--initio study},
author = {Alessandro Stroppa and Martijn Marsman and Georg Kresse and Silvia Picozzi},
journal= {arXiv preprint arXiv:0912.3345},
year = {2015}
}