Hu, Pengcheng ; Huang, Binxiang ; Breckmecker, Daniel ; Koruza, Jurij ; Albe, Karsten ; Klein, Andreas (2024)
Fermi level limitation in Na1/2Bi1/2TiO3–BaTiO3 piezoceramics by electrochemical reduction of Bi.
In: Journal of Applied Physics, 2024 (136)
doi: 10.1063/5.0227698
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The (electro)chemical stability of undoped and Zn-doped 0.94Na1/2Bi1/2TiO3–0.06BaTiO3 lead-free piezoceramics (NBT–6BT) was studied. For this purpose, the Fermi level at the interface between NBT–6BT and Sn-doped In2O3 (ITO) electrode is varied by gradually reducing the ITO film either by annealing in vacuum or by applying a voltage across a Pt/NBT–6BT/ITO. The chemical and electronic changes are monitored in situ by x-ray photoelectron spectroscopy. The experiments reveal the formation of metallic Bi when the Fermi level is reaching a value of 2.23 ± 0.10 eV above the valence band maximum, while no reduction of Ti is observed. The electrochemical reduction of Bi constitutes an upper limit of the Fermi level at ≈1 eV below the conduction band minimum. High electron concentrations in the conduction band and a contribution of free electrons to the electrical conductivity of NBT–6BT can, therefore, be excluded. The reduction occurs for an ITO work function of 4.2–4.3 eV. As typical electrode materials such as Ag, Cu, Ni, or Pt have higher work functions, an electrochemical instability of the electrode interfaces in ceramic capacitors is not expected. Under the given experimental conditions (350 °C, electric fields <40 V/mm), no degradation of resistance and no enrichment of Na at the interface are observed.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2024 |
| Autor(en): | Hu, Pengcheng ; Huang, Binxiang ; Breckmecker, Daniel ; Koruza, Jurij ; Albe, Karsten ; Klein, Andreas |
| Art des Eintrags: | Bibliographie |
| Titel: | Fermi level limitation in Na1/2Bi1/2TiO3–BaTiO3 piezoceramics by electrochemical reduction of Bi |
| Sprache: | Englisch |
| Publikationsjahr: | 17 September 2024 |
| Ort: | Melville, NY |
| Verlag: | AIP Publishing |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Applied Physics |
| Jahrgang/Volume einer Zeitschrift: | 2024 |
| (Heft-)Nummer: | 136 |
| Kollation: | 11 Seiten |
| DOI: | 10.1063/5.0227698 |
| URL / URN: | https://pubs.aip.org/aip/jap/article/136/11/114101/3312989/F... |
| Kurzbeschreibung (Abstract): | The (electro)chemical stability of undoped and Zn-doped 0.94Na1/2Bi1/2TiO3–0.06BaTiO3 lead-free piezoceramics (NBT–6BT) was studied. For this purpose, the Fermi level at the interface between NBT–6BT and Sn-doped In2O3 (ITO) electrode is varied by gradually reducing the ITO film either by annealing in vacuum or by applying a voltage across a Pt/NBT–6BT/ITO. The chemical and electronic changes are monitored in situ by x-ray photoelectron spectroscopy. The experiments reveal the formation of metallic Bi when the Fermi level is reaching a value of 2.23 ± 0.10 eV above the valence band maximum, while no reduction of Ti is observed. The electrochemical reduction of Bi constitutes an upper limit of the Fermi level at ≈1 eV below the conduction band minimum. High electron concentrations in the conduction band and a contribution of free electrons to the electrical conductivity of NBT–6BT can, therefore, be excluded. The reduction occurs for an ITO work function of 4.2–4.3 eV. As typical electrode materials such as Ag, Cu, Ni, or Pt have higher work functions, an electrochemical instability of the electrode interfaces in ceramic capacitors is not expected. Under the given experimental conditions (350 °C, electric fields <40 V/mm), no degradation of resistance and no enrichment of Na at the interface are observed. |
| Freie Schlagworte: | Condensed matter electronic structure, Electrical conductivity, Ionic conductivity, Electronic band structure, Work functions, Annealing, X-ray photoelectron spectroscopy, Ceramics, Defect diffusion, Electrochemistry |
| ID-Nummer: | Artikel-ID: 114101 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Elektronenstruktur von Materialien 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialmodellierung DFG-Sonderforschungsbereiche (inkl. Transregio) DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 1548: FLAIR – Fermi Level Engineering Applied to Oxide Electroceramics |
| Hinterlegungsdatum: | 15 Nov 2024 15:04 |
| Letzte Änderung: | 15 Nov 2024 15:04 |
| PPN: | 523600534 |
| Export: | |
| Suche nach Titel in: | TUfind oder in Google |
 |
Frage zum Eintrag |
Optionen (nur für Redakteure)
 |
Redaktionelle Details anzeigen |
Drucken
Impressum