Preparation and Thermoelectric Properties of Al₂O₃-Doped ZnO Ceramics

Abstract:

Al2O3-doped ZnO ceramics were prepared via chemical co-precipitation processing. Zinc acetate, ammonia and Al2O3 powders are used as starting materials. Scanning electron microscopy (SEM) observations reveal that the doping of Al2O3 has an obvious influence on the microstructure of ZnO ceramics. Ordinary cold pressing and cold isostatic pressing (CIP) were used to prepare green compacts. The thermal conductivity and electrical conductivity of the Al2O3-doped ZnO ceramics were measured as a function of the testing temperature (0-900oC). Doping of Al2O3 is beneficial to improve thermoelectric (TE) properties of ZnO ceramics. CIP can also improve TE properties of Al2O3-doped ZnO ceramics.

• Periodical: Key Engineering Materials (Volumes 368-372)
• Pages: 562-564
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.368-372.562
• Online since: February 2008
• Authors: Xiu Rong Qu, De Chang Jia
• Keywords: Al₂O₃-Doped ZnO , Microstructure, Powder, Thermoelectric Property

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200 400 600 800 1000.

[5] [10] [15] [20] [25] [30] cold pressing CIP κ(W/m/K) Temperature(oC) (a).

200 400 600 800 1000.

[2] [4] [6] [8] [10] [12] [14] cold pressing CIP κ(W/m/K) Temperature(oC) (b).

200 400 600 800 1000 0. 0 0. 2 0. 4 0. 6 0. 8 1. 0 1. 2 δ(S/cm) Temperature (oC) CIP cold pressing (c).

200 400 600 800 1000.

[2] [4] [6] [8] [10] Temperature (o C) cold pressing δ(S/cm) CIP (d) Fig. 4 (a) Thermal conductivity of pure ZnO ceramics, (b) 3wt% Al2O3-doped ZnO ceramics after cold pressing and CIP, respectively, (c) Electrical conductivity of pure ZnO ceramics, (d) 3wt% Al2O3-doped ZnO ceramics after cold pressing and CIP, respectively.

DOI: 10.1016/j.ceramint.2006.01.006

200 400 600 800 1000 0. 00 0. 05 0. 10 0. 15 0. 20 0. 25 0. 30 0% δ(S/cm) Temperature ( o C) 1% 3% (a).

200 400 600 800 1000.

[5] [10] [15] [20] [25] κ(W/mK) Temperature(oC) (b) 0% 1% 3% Fig. 3 Temperature dependence of (a) electrical conductivity; (b) thermal conductivity of the samples sintered at 1000 o C after cold pressing with different amounts of Al2O3.