High temperature oxidation behavior of cobalt triantimonide thermoelectric material
High temperature oxidation behavior of cobalt triantimonide thermoelectric material
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DOI：
10.1016/j.jallcom.2010.05.160
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发表时间：
2010-08
影响因子：
6.2
通讯作者：
Degang Zhao;C. Tian;Shouqiu Tang;Yun-teng Liu;Lidong Chen
中科院分区：
文献类型：
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作者：
Degang Zhao;C. Tian;Shouqiu Tang;Yun-teng Liu;Lidong Chen
研究了CoSb 3热电材料在500°C ~ 650°C空气中的氧化行为。结果表明，CoSb 3材料在500°C ~ 600°C范围内的氧化膜生长服从抛物线规律，而在650°C时由于Sb 2 O 3的升华，氧化膜发生了严重的失重。CoSb_3的氧化活化能为37.4kJ/mol。SEM和XRD结果表明，CoSb 3在600°C以下氧化时，氧化膜为Sb 2 O3和CoSb 2 O 6的混合物;而在650°C氧化时，氧化膜由外层Sb 2 O3和内层Sb 2 O3和CoSb 2 O 6组成。氧化一定时间后，氧化膜/CoSb 3界面出现裂纹。探讨了CoSb 3材料的氧化机理。在650°C氧化48 h后，CoSb 3的热电性能明显下降，ZT值从0.24下降到327°C时的0.17。
The oxidation behavior of CoSb3thermoelectric material in air has been studied from 500°C to 650°C. The present work showed that the growth of oxide scale on CoSb3material obeyed a parabolic law from 500°C to 600°C, while tremendous weight loss occurred at 650°C owing to the sublimation of Sb2O3. The oxidation activation energy of CoSb3was estimated to be 37.4kJ/mol. SEM and XRD results showed that the oxide scale of CoSb3was the mixture of Sb2O3and CoSb2O6when CoSb3was oxidized below 600°C; whereas the oxide scale consisted of an outer layer of Sb2O3and an inner layer, which was composed of Sb2O3and CoSb2O6, when CoSb3was oxidized at 650°C. Cracks appeared at the scale/CoSb3interface after a certain oxidation time. The oxidation mechanism of CoSb3material was discussed. After oxidation at 650°C for 48h, thermoelectric performance of CoSb3declined obviously and ZT value decreased from 0.24 to 0.17 at 327°C.