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Stöcker, Thomas ; Dauner, Peter ; Moos, Ralf:
Thermoelectric properties of the different phases of CuFe2O4 prepared by aerosol deposition.
2015
Veranstaltung: 90. DKG Jahrestagung / Symposium Hochleistungskeramik 2015
, 15.-19.03.2015
, Bayreuth, Deutschland.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung
,
Sonstige
Präsentationstyp)
Abstract
In this study, the thermoelectric properties of tetragonal and cubic CuFe2O4, a cuprospinel, were investigated. For this purpose, the cuprospinel was synthetized by a conventional mixed-oxide technique and calcined at 1000 °C. X-ray diffraction studies revealed that tetragonal CuFe2O4 arises when slowly cooling down the cuprospinel in a thermodynamic equilibrium. Given that the cubic system is the hightemperature phase of CuFe2O4, the calcined powder was quenched to roomtemperature in order to obtain cubic cuprospinel.
After conducting X-ray diffraction studies to verify the crystal structure of the synthesized cuprospinel, the novel Aerosol Deposition (AD) coating technique was employed to prepare ceramic films. This technology bases upon a room temperature impact consolidation process (RTIC) to deposit dense solid films of ceramic materials on various substrates without using a high-temperature step during the coating process. By employing this AD method, it was possible to obtain non-porous, dense ceramic films of 10 μm thickness, of both tetragonal and cubic CuFe2O4 at room temperature.
By using a modulation heater to impress an oscillating temperature gradient over the samples, the Seebeck coefficient and the electrical conductivity were measured between room-temperature and 800 °C. Our results indicate that tetragonal as well as cubic CuFe2O4 are p-type semiconductors at room temperature but apparently run through a phase-transition at 400 °C, resulting in a change of the conduction mechanism from p-type to n-type at high temperatures yet remaining n-type when cooling down to room temperature.
Since this mechanism hasn’t been observed for cuprospinel so far, this study helps to gain more knowledge of the thermoelectric properties of CuFe2O4.
Weitere Angaben
| Publikationsform: | Veranstaltungsbeitrag (Sonstige) |
|---|---|
| Begutachteter Beitrag: | Ja |
| Institutionen der Universität: | Fakultäten > Fakultät für Ingenieurwissenschaften Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien > Lehrstuhl Funktionsmaterialien - Univ.-Prof. Dr.-Ing. Ralf Moos Fakultäten Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien Profilfelder > Advanced Fields > Neue Materialien Forschungseinrichtungen > Forschungszentren > Bayreuther Materialzentrum - BayMAT Profilfelder Profilfelder > Advanced Fields Forschungseinrichtungen Forschungseinrichtungen > Forschungszentren |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften |
| Eingestellt am: | 11 Mai 2015 09:53 |
| Letzte Änderung: | 18 Apr 2016 07:09 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/13157 |