Coupling between ionic defect structure and electronic conduction in passive films on iron, chromium and iron-chromium alloys

Martin Bojinov (Corresponding Author), Gunilla Fabricius, Timo Laitinen, Kari Mäkelä, Timo Saario, Göran Sundholm

    Research output: Contribution to journalArticleScientificpeer-review

    147 Citations (Scopus)

    Abstract

    A quantitative kinetic model is presented for the steady-state passive films on Fe, Cr and Fe–Cr alloys. It emphasises the coupling between the ionic defect structure and electronic conduction. According to the model, the passive film can be represented as a heavily doped n-type semiconductor–insulator-p-type semiconductor junction. At low potentials in the passive state, the positive defects injected at the metal/film interface play the role of electron donors. At high positive potentials, the negative defects injected at the film/solution interface play the role of electron acceptors. At sufficiently high positive potentials the concentration of these ionic defects and corresponding electron holes reaches high enough values for the film to transform into a conductor. This enables transpassive dissolution of Cr and oxygen evolution on the film surface. Equations for the electronic conductivity of the passive film, as depending on the concentration of point defects, are derived. The proposed model is compared with experimental data obtained for pure Fe, pure Cr, Fe–12%Cr alloy and Fe–25%Cr alloy passivated in 0.1 M borate solution (pH 9.2) using rotating ring-disk voltammetry, photocurrent and impedance spectroscopy and in situ dc resistance measurements by the contact electric resistance (CER) technique.

    Original languageEnglish
    Pages (from-to)2029 - 2048
    Number of pages20
    JournalElectrochimica Acta
    Volume45
    Issue number13
    DOIs
    Publication statusPublished - 2000
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    Chromium Alloys
    Chromium alloys
    Iron alloys
    Defect structures
    Chromium
    Iron
    Defects
    Electrons
    Semiconductor junctions
    Electric contacts
    Borates
    Point defects
    Voltammetry
    Photocurrents
    Dissolution
    Metals
    Spectroscopy
    Oxygen
    Kinetics

    Cite this

    Bojinov, Martin ; Fabricius, Gunilla ; Laitinen, Timo ; Mäkelä, Kari ; Saario, Timo ; Sundholm, Göran. / Coupling between ionic defect structure and electronic conduction in passive films on iron, chromium and iron-chromium alloys. In: Electrochimica Acta. 2000 ; Vol. 45, No. 13. pp. 2029 - 2048.
    @article{afdfb9038977401ebd3b11f7e2f69999,
    title = "Coupling between ionic defect structure and electronic conduction in passive films on iron, chromium and iron-chromium alloys",
    abstract = "A quantitative kinetic model is presented for the steady-state passive films on Fe, Cr and Fe–Cr alloys. It emphasises the coupling between the ionic defect structure and electronic conduction. According to the model, the passive film can be represented as a heavily doped n-type semiconductor–insulator-p-type semiconductor junction. At low potentials in the passive state, the positive defects injected at the metal/film interface play the role of electron donors. At high positive potentials, the negative defects injected at the film/solution interface play the role of electron acceptors. At sufficiently high positive potentials the concentration of these ionic defects and corresponding electron holes reaches high enough values for the film to transform into a conductor. This enables transpassive dissolution of Cr and oxygen evolution on the film surface. Equations for the electronic conductivity of the passive film, as depending on the concentration of point defects, are derived. The proposed model is compared with experimental data obtained for pure Fe, pure Cr, Fe–12{\%}Cr alloy and Fe–25{\%}Cr alloy passivated in 0.1 M borate solution (pH 9.2) using rotating ring-disk voltammetry, photocurrent and impedance spectroscopy and in situ dc resistance measurements by the contact electric resistance (CER) technique.",
    author = "Martin Bojinov and Gunilla Fabricius and Timo Laitinen and Kari M{\"a}kel{\"a} and Timo Saario and G{\"o}ran Sundholm",
    note = "Project code: V9SU00119",
    year = "2000",
    doi = "10.1016/S0013-4686(99)00423-5",
    language = "English",
    volume = "45",
    pages = "2029 -- 2048",
    journal = "Electrochimica Acta",
    issn = "0013-4686",
    publisher = "Elsevier",
    number = "13",

    }

    Coupling between ionic defect structure and electronic conduction in passive films on iron, chromium and iron-chromium alloys. / Bojinov, Martin (Corresponding Author); Fabricius, Gunilla; Laitinen, Timo; Mäkelä, Kari; Saario, Timo; Sundholm, Göran.

    In: Electrochimica Acta, Vol. 45, No. 13, 2000, p. 2029 - 2048.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Coupling between ionic defect structure and electronic conduction in passive films on iron, chromium and iron-chromium alloys

    AU - Bojinov, Martin

    AU - Fabricius, Gunilla

    AU - Laitinen, Timo

    AU - Mäkelä, Kari

    AU - Saario, Timo

    AU - Sundholm, Göran

    N1 - Project code: V9SU00119

    PY - 2000

    Y1 - 2000

    N2 - A quantitative kinetic model is presented for the steady-state passive films on Fe, Cr and Fe–Cr alloys. It emphasises the coupling between the ionic defect structure and electronic conduction. According to the model, the passive film can be represented as a heavily doped n-type semiconductor–insulator-p-type semiconductor junction. At low potentials in the passive state, the positive defects injected at the metal/film interface play the role of electron donors. At high positive potentials, the negative defects injected at the film/solution interface play the role of electron acceptors. At sufficiently high positive potentials the concentration of these ionic defects and corresponding electron holes reaches high enough values for the film to transform into a conductor. This enables transpassive dissolution of Cr and oxygen evolution on the film surface. Equations for the electronic conductivity of the passive film, as depending on the concentration of point defects, are derived. The proposed model is compared with experimental data obtained for pure Fe, pure Cr, Fe–12%Cr alloy and Fe–25%Cr alloy passivated in 0.1 M borate solution (pH 9.2) using rotating ring-disk voltammetry, photocurrent and impedance spectroscopy and in situ dc resistance measurements by the contact electric resistance (CER) technique.

    AB - A quantitative kinetic model is presented for the steady-state passive films on Fe, Cr and Fe–Cr alloys. It emphasises the coupling between the ionic defect structure and electronic conduction. According to the model, the passive film can be represented as a heavily doped n-type semiconductor–insulator-p-type semiconductor junction. At low potentials in the passive state, the positive defects injected at the metal/film interface play the role of electron donors. At high positive potentials, the negative defects injected at the film/solution interface play the role of electron acceptors. At sufficiently high positive potentials the concentration of these ionic defects and corresponding electron holes reaches high enough values for the film to transform into a conductor. This enables transpassive dissolution of Cr and oxygen evolution on the film surface. Equations for the electronic conductivity of the passive film, as depending on the concentration of point defects, are derived. The proposed model is compared with experimental data obtained for pure Fe, pure Cr, Fe–12%Cr alloy and Fe–25%Cr alloy passivated in 0.1 M borate solution (pH 9.2) using rotating ring-disk voltammetry, photocurrent and impedance spectroscopy and in situ dc resistance measurements by the contact electric resistance (CER) technique.

    U2 - 10.1016/S0013-4686(99)00423-5

    DO - 10.1016/S0013-4686(99)00423-5

    M3 - Article

    VL - 45

    SP - 2029

    EP - 2048

    JO - Electrochimica Acta

    JF - Electrochimica Acta

    SN - 0013-4686

    IS - 13

    ER -