Poling-Written Ferroelectricity in Bulk Multiferroic Double-Perovskite BiFe0.5Mn0.5O3

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• 作者：Davide Delmonte ; Francesco Mezzadri ; Edmondo Gilioli ; Massimo Solzi ; Gianluca Calestani ; Fulvio Bolzoni ; Riccardo Cabassi
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：June 20, 2016
• 年：2016
• 卷：55
• 期：12
• 页码：6308-6314
• 全文大小：407K
• 年卷期：0
• ISSN：1520-510X

文摘

We present a comprehensive study of the electrical properties of bulk polycrystalline BiFe_0.5Mn_0.5O₃, a double perovskite synthesized in high-pressure and high-temperature conditions. BiFe_0.5Mn_0.5O₃ shows an antiferromagnetic character with T_N = 288 K overlapped with an intrinsic antiferroelectricity due to the Bi³⁺ stereochemical effect. Beyond this, the observation of a semiconductor–insulator transition at T_P ≈ 140 K allows one to define three distinct temperature ranges with completely different electrical properties. For T > T_N, electric transport follows an ordinary thermally activated Arrhenius behavior; the system behaves as a paramagnetic semiconductor. At intermediate temperatures (T_P < T < T_N), 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 < T_P, 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.