微結構與熱電性能
(寧波工程學院 機械工程學院， 寧波 315016)
摘 要: 采用SPS法制備了p-型四元Al-Bi-Sb-Te合金， 研究其微結構和熱電性能。 結果表明： Al含量直接影響材料的電、熱學輸運性能。 當材料中Al替代Sb元素后， 四元合金AlxBi0.5Sb1.5-xTe3 (x=0.05~0.2)的電導率明顯增大； 在室溫附近，x=0.1的合金其電導率可達3.3×104 Ω-1·m-1， 大約是三元Bi0.5Sb1.5Te3合金的2倍； 四元合金系的最小Seebeck系數(shù)α為115 μV/K， 說明材料屬p-型半導體；當溫度為411 K時， 合金AlxBi0.5Sb1.5-xTe3(x=0.1)的ZT值出現(xiàn)最大值， 其值為0.58， 是同溫度下典型三元Bi0.5Sb1.5Te3合金的1.6倍。
關鍵字: 四元Al-Bi-Sb-Te合金； 放電等離子燒結系統(tǒng)； 微結構；熱電性能
（School of Mechanical Engineering,
Ningbo University of Technology, Ningbo 315016, China）
Abstract: The microstructures and thermoelectric properties of p-type quaternary Al-Bi-Sb-Te alloys fabricated by spark plasma sintering technique were investigated. The results reveal that the crystal constants are directly related to Al content that is critical to determine the electrical and thermal conductivities. The electrical conductivity (σ) of 3.3× 104 Ω-1·m-1 for AlxBi0.5Sb1.5-xTe3 alloy (x=0.1) was obtained near room temperature, which is twice as large as that of ternary Bi0.5Sb1.5Te3 alloy. The minimum Seebeck coefficient (α) of all the quaternary Al-Bi-Sb-Te alloys is 115 μV/K, indicating p-type conducting behavior. The dimensionless figure of merit (ZT) of 0.58 is achieved at 411 K, being about 1.6 times as large as that of typical ternary Bi0.5Sb1.5Te3 alloy at the same temperature.
Key words: quaternary Al-Bi-Sb-Te alloys; spark plasma sintering(SPS); microstructures; thermoelectric properties
