微结构与热电性能
(宁波工程学院 机械工程学院， 宁波 315016)
摘 要: 采用SPS法制备了p-型四元Al-Bi-Sb-Te合金， 研究其微结构和热电性能。 结果表明： Al含量直接影响材料的电、热学输运性能。 当材料中Al替代Sb元素后， 四元合金AlxBi0.5Sb1.5-xTe3 (x=0.05~0.2)的电导率明显增大； 在室温附近，x=0.1的合金其电导率可达3.3×104 Ω-1·m-1， 大约是三元Bi0.5Sb1.5Te3合金的2倍； 四元合金系的最小Seebeck系数α为115 μV/K， 说明材料属p-型半导体；当温度为411 K时， 合金AlxBi0.5Sb1.5-xTe3(x=0.1)的ZT值出现最大值， 其值为0.58， 是同温度下典型三元Bi0.5Sb1.5Te3合金的1.6倍。
关键字: 四元Al-Bi-Sb-Te合金； 放电等离子烧结系统； 微结构；热电性能
（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
