Ab initio investigation of Fe$^{2 }$-Fe$^{3 }$ dimerization and ferroelectricity in multiferroic magnetite: role of electronic correlations - Condensed Matter > Materials ScienceReportar como inadecuado




Ab initio investigation of Fe$^{2 }$-Fe$^{3 }$ dimerization and ferroelectricity in multiferroic magnetite: role of electronic correlations - Condensed Matter > Materials Science - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: Based on ab initio density functional theory, we have investigated amicroscopic mechanism that leads to Fe$^{2+} {B}$-Fe$^{3+} {B}$ dimerizationand consequent ferroelectricity in charge ordered Fe$ {3}$O$ {4}$ with $P2$symmetry. In addition to the simple inter-site Coulomb repulsion, quantumhybridization effects are invoked to explain the Fe$^{2+} {B}$-Fe$^{3+} {B}$bond dimerization. Our results, based on the generalized gradient approximation+ Hubbard $U$ GGA+$U$ method, indicate that noncentrosymmetric $P2$ magnetiteshows a finite and sizeable ferroelectric polarization along the $b$crystalline axis. From the $U$ dependence of polarization, we conclude that theorigin of ferroelectricity in $P2$ Fe$ {3}$O$ {4}$ lies in the recentlyproposed -intermediate site-bond-centered charge ordering-.



Autor: Tetsuya Fukushima, Kunihiko Yamauchi, Silvia Picozzi

Fuente: https://arxiv.org/



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