β-FeSi2의 열전변환특성에 미치는 분말산화의 영향 |
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The Effect of Powder Oxidation on the Thermoelectric Properties of β-FeSi2 |
배철훈 , Kunihito Koumoto 1 |
인천대학교 신소재공학과 1Department of Applied Chemistry, Nagoya University |
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ABSTRACT |
For the purpose of making clear the role of oxygen in the thermoelectric properties of FeSi$_2$, thermoelectric measurements and spectroscopic characterization were conducted for the oxidized specimens fabricated from ($alpha$+$varepsilon$)-phases and/or $beta$-phase. Addition of oxygen to FeSi$_2$ prevented both densification during sintering and transformation from metallic phases to semiconducting phase during annealing treatment. In an specimens, electrical conductivity and thermal conductivity decreased with oxidation time. The Seebeck coefficient was positive and small for pure FeSi$_2$. And/or the oxidized specimens fabricated from ($alpha$+$varepsilon$)-phases. However, it was negative and showed a maximum peak at about 500 K for the oxidized FeSi$_2$ fabricated from $beta$-phase. The value of maximum peak increased with oxidation time. |
Key words:
$\beta$-$FeSi_2$ : $\varepsilon$-FeSi, $\alpha$-$Fe_2$$Si_5$, Powder oxidation, Electrical conductivity, Seebeck coefficient, Thermal conductivity, Figure of merit |
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