title: Multiferroic materials based on organic transition-metal molecular nanowires.
abstract: We report on the density functional theory aided design of a variety of organic ferroelectric and multiferroic materials by functionalizing crystallized transition-metal molecular sandwich nanowires with chemical groups such as -F, -Cl, -CN, -NO(2), ═O, and -OH. Such functionalized polar wires exhibit molecular reorientation in response to an electric field. Ferroelectric polarizations as large as 23.0 μC/cm(2) are predicted in crystals based on fully hydroxylized sandwich nanowires. Furthermore, we find that organic nanowires formed by sandwiching transition-metal atoms in croconic and rhodizonic acids, dihydroxybenzoquinone, dichloro-dihydroxy-p-benzoquinone, or benzene decorated by -COOH groups exhibit ordered magnetic moments, leading to a multiferroic organometallic crystal. When crystallized through hydrogen bonds, the microscopic molecular reorientation translates into a switchable polarization through proton transfer. A giant interface magnetoelectric response that is orders of magnitude greater than previously reported for conventional oxide heterostructure interfaces is predicted.
authors.affiliation: Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284, USA. mwu2@vcu.edu
authors.forename: Menghao
authors.initials: M
authors.lastname: Wu
authors.forename: J D
authors.initials: JD
authors.lastname: Burton
authors.forename: Evgeny Y
authors.initials: EY
authors.lastname: Tsymbal
authors.forename: Xiao Cheng
authors.initials: XC
authors.lastname: Zeng
authors.forename: Puru
authors.initials: P
authors.lastname: Jena