((1. 浙江工業(yè)大學(xué) 化學(xué)工程與材料學(xué)院，杭州 310014；2. 寧波工程學(xué)院 機(jī)械工程學(xué)院，寧波 315016；3. 中國礦業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，徐州 221008))
摘 要: 采用真空熔煉/放電等離子燒結(jié)(SPS)方法制備P型Zn4−xCuxSb3−xBix(x=0~0.8)材料，研究該合金的組織結(jié)構(gòu)和熱電性能。結(jié)果表明，x＜0.2時(shí)，Zn4−xCuxSb3−xBix材料的Seebeck系數(shù)隨x值增大而增大，當(dāng)x=0.2時(shí)達(dá)到最大值；而當(dāng)x＞0.2后，Seebeck系數(shù)又隨x值增大而下降。在x=0.2和487 K的條件下，Seebeck系數(shù)達(dá)到最大值，為249.2 mV/K。合金的電導(dǎo)率隨Cu和Bi含量增加而增大。借助Zn4-xCuxSb3的熱擴(kuò)散系數(shù)，計(jì)算得到材料的熱導(dǎo)率隨x值增大而增大；在574 K，x=0.4時(shí)，Zn4−xCuxSb3−xBix合金的最大熱電優(yōu)值(ZT)為0.53，比同溫度下b-Zn4Sb3合金的ZT值大0.07。
關(guān)鍵字: Zn-Cu-Sb-Bi合金；共摻雜；熱電性能；放電等離子燒結(jié)
（(1. College of Chemical Engineering and Materials Science, Zhejiang University of Technology,Hangzhou 310014, China;2. School of Mechanical Engineering, Ningbo University of Technology, Ningbo 315016, China;3. School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221008, China)）
Abstract:P-type Zn4−xCuxSb3−xBix (x=0−0.8) alloys were prepared through vacuum melting and spark plasma sintering, and their structures were characterized. The results show that the Seebeck coefficient () increases with molar fraction (x) up to x=0.2 and then decreases, the electrical conductivity (σ) increases with increasing molar fraction x value. Considering the same fabrication technology of Zn4−xCuxSb3−xBix and Zn4−xCuxSb3 with the same x, the measured thermal diffusivities of Zn4−xCuxSb3 were used to calculate the thermal conductivities of Zn4−xCuxSb3−xBix. A relative enhancement of ZT is attained for Zn3.6Cu0.4Sb3.6Bi0.4, whose ZT is 0.53 at 574 K, about 0.07 higher than that of Zn4Sb3 at the same temperature.
Key words: Zn-Cu-Sb-Bi alloys; co-doping; thermoelectric properties; spark plasma sintering (SPS)
