Microstructural analysis and thermoelectric properties of Sn-Al co-doped ZnO ceramics

Journal Article · Fri Aug 26 00:00:00 EDT 2016 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4961357· OSTI ID:22608254

Hoemke, Joshua; Tochigi, Eita; Shibata, Naoya; Ikuhara, Yuichi ^[1]; Khan, Atta Ullah; Mori, Takao ^[2]; Yoshida, Hidehiro; Sakka, Yoshio ^[3]

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1. Institute of Engineering Innovation, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)
2. National Institute of Materials Science (NIMS) 1-1 Namiki, Tsukuba 305-0044 (Japan)
3. National Institute of Materials Science (NIMS), 1–2–1 Sengen, Tsukuba, 305–0047 (Japan)

Sn-Al co-doped polycrystalline ZnO ceramics were prepared by sintering in air. Phase and microstructure analysis was performed by X-ray diffraction and SEM-EDS and thermoelectric properties were measured. XRD analysis showed a ZnO primary phase as well as secondary phase peaks due to the formation of a Zn{sub 2}SnO{sub 4} spinel phase or SnO{sub 2}(ZnO:Sn-Al){sub m} intergrowth phase. SEM analysis revealed a dense microstructure with a small number of nanometric pores, consistent with the measured density of 5.48 g/cm{sup 3}. An activated electrical conductivity characteristic of a semiconducting material was observed as well as a negative Seebeck coefficient with both values increasing in absolute value from RT to 730 °C. The power factor had a maximum value of 3.73×10{sup −4} W m{sup −1} K{sup −2} at 730 °C. Thermal conductivity measurements showed a significant reduction over the measured temperature range compared to undoped ZnO. This could be attributed to grain size reduction, the formation of a nanoscale secondary phase or a reduction in crystallinity caused by Sn-Al co-doping. A maximum ZT of 0.06 was obtained at 750 °C for the Sn-Al co-doped ZnO ceramics.

• OSTI ID: 22608254
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1763; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM ADDITIONS
CERAMICS
COMPARATIVE EVALUATIONS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
GRAIN SIZE
MICROSTRUCTURE
NANOSTRUCTURES
POLYCRYSTALS
POWER FACTOR
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SINTERING
SPINELS
THERMAL CONDUCTIVITY
THERMOELECTRIC PROPERTIES
TIN ADDITIONS
TIN OXIDES
X-RAY DIFFRACTION
ZINC OXIDES