Bein, Nicole S. ; Kmet, Brigita ; Rojac, Tadej ; Golob, Andreja Benčan ; Malič, Barbara ; Moxter, Julian ; Schneider, Thorsten ; Fulanovic, Lovro ; Azadeh, Maryam ; Frömling, Till ; Egert, Sonja ; Wang, Hongguang ; Aken, Peter van ; Schwarzkopf, Jutta ; Klein, Andreas (2022)
Fermi energy, electrical conductivity, and the energy gap of NaNbO3.
In: Physical Review Materials, 6 (8)
doi: 10.1103/PhysRevMaterials.6.084404
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The energy of the valence band maximum of NaNbO3 is determined from the Schottky barrier heights at the contacts with low work function Sn-doped In2O3 and high work function RuO2 by means of x-ray photoelectron spectroscopy with in situ interface preparation. The measurements reveal a valence-band edge energy, which is comparable to that of SrTiO3 and BaTiO3. The energy gap of SrTiO3 and BaTiO3 is 3.2eV and comparable to the values of 3.4eVto3.5eV, which are determined by means of optical and electron energy loss spectroscopy for NaNbO3. It is therefore expected that the conduction band minimum of NaNbO3 is also located at a similar energy as the conduction band minimum of SrTiO3 and BaTiO3. If this is the case, it can be expected that donor doping of NaNbO3 leads to an electrical conductivity, which is comparable to those of donor-doped SrTiO3 and BaTiO3 (up to ∼ 1S/cm−1). In contrast, Sr- and Ca-doped NaNbO3 bulk ceramics exhibit a room temperature conductivity up to 10×10−10S/cm−1, only slightly higher than that of NaNbO3. High-field conductivity measurements and impedance spectroscopy give no indication that the low conductivity is caused by insulating grain boundaries separating electrically conductive grains. It is therefore suggested that the energy gap of NaNbO3 is substantially higher than the gap of 3.4eVto3.5eV determined from optical spectroscopy reported in literature and from electron energy loss spectroscopy within this paper, as also suggested from electronic structure calculations of LiNbO3
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2022 |
| Autor(en): | Bein, Nicole S. ; Kmet, Brigita ; Rojac, Tadej ; Golob, Andreja Benčan ; Malič, Barbara ; Moxter, Julian ; Schneider, Thorsten ; Fulanovic, Lovro ; Azadeh, Maryam ; Frömling, Till ; Egert, Sonja ; Wang, Hongguang ; Aken, Peter van ; Schwarzkopf, Jutta ; Klein, Andreas |
| Art des Eintrags: | Bibliographie |
| Titel: | Fermi energy, electrical conductivity, and the energy gap of NaNbO3 |
| Sprache: | Englisch |
| Publikationsjahr: | 3 August 2022 |
| Verlag: | American Physical Society |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Physical Review Materials |
| Jahrgang/Volume einer Zeitschrift: | 6 |
| (Heft-)Nummer: | 8 |
| DOI: | 10.1103/PhysRevMaterials.6.084404 |
| Kurzbeschreibung (Abstract): | The energy of the valence band maximum of NaNbO3 is determined from the Schottky barrier heights at the contacts with low work function Sn-doped In2O3 and high work function RuO2 by means of x-ray photoelectron spectroscopy with in situ interface preparation. The measurements reveal a valence-band edge energy, which is comparable to that of SrTiO3 and BaTiO3. The energy gap of SrTiO3 and BaTiO3 is 3.2eV and comparable to the values of 3.4eVto3.5eV, which are determined by means of optical and electron energy loss spectroscopy for NaNbO3. It is therefore expected that the conduction band minimum of NaNbO3 is also located at a similar energy as the conduction band minimum of SrTiO3 and BaTiO3. If this is the case, it can be expected that donor doping of NaNbO3 leads to an electrical conductivity, which is comparable to those of donor-doped SrTiO3 and BaTiO3 (up to ∼ 1S/cm−1). In contrast, Sr- and Ca-doped NaNbO3 bulk ceramics exhibit a room temperature conductivity up to 10×10−10S/cm−1, only slightly higher than that of NaNbO3. High-field conductivity measurements and impedance spectroscopy give no indication that the low conductivity is caused by insulating grain boundaries separating electrically conductive grains. It is therefore suggested that the energy gap of NaNbO3 is substantially higher than the gap of 3.4eVto3.5eV determined from optical spectroscopy reported in literature and from electron energy loss spectroscopy within this paper, as also suggested from electronic structure calculations of LiNbO3 |
| ID-Nummer: | Artikel-ID: 084404 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Dünne Schichten 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Elektronenstruktur von Materialien 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Nichtmetallisch-Anorganische Werkstoffe 18 Fachbereich Elektrotechnik und Informationstechnik 18 Fachbereich Elektrotechnik und Informationstechnik > Institut für Elektrische Energiesysteme > Hochspannungstechnik 18 Fachbereich Elektrotechnik und Informationstechnik > Institut für Elektrische Energiesysteme LOEWE LOEWE > LOEWE-Schwerpunkte LOEWE > LOEWE-Schwerpunkte > FLAME - Fermi Level Engineering Antiferroelektrischer Materialien für Energiespeicher und Isolatoren 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 09 Jan 2023 07:03 |
| Letzte Änderung: | 06 Nov 2024 13:37 |
| PPN: | 503501824 |
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