title: Evidence for room-temperature multiferroicity in a compound with a giant axial ratio.
abstract: In the search for multiferroic materials magnetic compounds with a strongly elongated unit-cell (large axial ratio c/a) have been scrutinized intensely. However, none was hitherto proven to have a switchable polarization, an essential feature of ferroelectrics. Here, we provide evidence for the epitaxial stabilization of a monoclinic phase of BiFeO3 with a giant axial ratio (c/a=1.23) that is both ferroelectric and magnetic at room temperature. Surprisingly, and in contrast with previous theoretical predictions, the polarization does not increase dramatically with c/a. We discuss our results in terms of the competition between polar and antiferrodistortive instabilities and give perspectives for engineering multiferroic phases.
authors.affiliation: Unité Mixte de Physique CNRS/Thales, Campus de l'Ecole Polytechnique, 1 Av. A. Fresnel, 91767 Palaiseau, France.
authors.forename: H
authors.initials: H
authors.lastname: Béa
authors.forename: B
authors.initials: B
authors.lastname: Dupé
authors.forename: S
authors.initials: S
authors.lastname: Fusil
authors.forename: R
authors.initials: R
authors.lastname: Mattana
authors.forename: E
authors.initials: E
authors.lastname: Jacquet
authors.forename: B
authors.initials: B
authors.lastname: Warot-Fonrose
authors.forename: F
authors.initials: F
authors.lastname: Wilhelm
authors.forename: A
authors.initials: A
authors.lastname: Rogalev
authors.forename: S
authors.initials: S
authors.lastname: Petit
authors.forename: V
authors.initials: V
authors.lastname: Cros
authors.forename: A
authors.initials: A
authors.lastname: Anane
authors.forename: F
authors.initials: F
authors.lastname: Petroff
authors.forename: K
authors.initials: K
authors.lastname: Bouzehouane
authors.forename: G
authors.initials: G
authors.lastname: Geneste
authors.forename: B
authors.initials: B
authors.lastname: Dkhil
authors.forename: S
authors.initials: S
authors.lastname: Lisenkov
authors.forename: I
authors.initials: I
authors.lastname: Ponomareva
authors.forename: L
authors.initials: L
authors.lastname: Bellaiche
authors.forename: M
authors.initials: M
authors.lastname: Bibes
authors.forename: A
authors.initials: A
authors.lastname: Barthélémy