title: Poling-Written Ferroelectricity in Bulk Multiferroic Double-Perovskite BiFe0.5Mn0.5O3.
abstract: We present a comprehensive study of the electrical properties of bulk polycrystalline BiFe0.5Mn0.5O3, a double perovskite synthesized in high-pressure and high-temperature conditions. BiFe0.5Mn0.5O3 shows an antiferromagnetic character with TN = 288 K overlapped with an intrinsic antiferroelectricity due to the Bi(3+) stereochemical effect. Beyond this, the observation of a semiconductor-insulator transition at TP ≈ 140 K allows one to define three distinct temperature ranges with completely different electrical properties. For T > TN, electric transport follows an ordinary thermally activated Arrhenius behavior; the system behaves as a paramagnetic semiconductor. At intermediate temperatures (TP < T < TN), electric transport is best described by Mott's variable range hopping model with lowered dimensionality D = 1, stabilized by the magnetic ordering process and driven by the inhomogeneity of the sample on the B site of the perovskite. Finally, for T < TP, the material becomes a dielectric insulator, showing very unusual poling-induced soft ferroelectricity with high saturation polarization, similar to the parent compound BiFeO3. Under external electric poling, the system irreversibly evolves from antiferroelectric to polar arrangement.
authors.affiliation: IMEM-CNR , Parco Area delle Scienze 37/A, 43124 Parma, Italy.|Department of Physics and Earth Science, University of Parma , Parco Area delle Scienze 7/A, 43124 Parma, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Delmonte
authors.affiliation: Department of Chemistry, University of Parma , Parco Area delle Scienze 17/A 43124 Parma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mezzadri
authors.affiliation: IMEM-CNR , Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: Edmondo
authors.initials: E
authors.lastname: Gilioli
authors.affiliation: Department of Physics and Earth Science, University of Parma , Parco Area delle Scienze 7/A, 43124 Parma, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Solzi
authors.affiliation: Department of Chemistry, University of Parma , Parco Area delle Scienze 17/A 43124 Parma, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Calestani
authors.affiliation: IMEM-CNR , Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Bolzoni
authors.affiliation: IMEM-CNR , Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Cabassi