(Sb_2Te_3)_(0.75(1-x))(Bi_2Te_3)_(0.25(1-x))(Sb_2Se_3)_x机械合金化粉体的制备及其冷压烧结样品的热电性能研究

Powders (Sb_2Te_3)_(0.75(1-x))(Bi_2Te_3)_(0.25(1-x))(Sb_2Se_3)_x prepared by mechanical alloying and thermoelectric properties of cold-pressed and sintered samples

采用机械合金化法制备了p型赝三元(Sb2Te3-Bi2Te3-Sb2Se3)合金粉体,对其进行XRD分析表明Te,Bi,Sb,Se单质粉末,经100h球磨后实现了合金化;SEM分析表明所得机械合金化粉体材料颗粒均匀、细小,颗粒尺寸在10nm到100nm量级.使用这种粉体制备了冷压烧结块体样品,在室温下测量了温差电动势率(α)和电导率(σ),研究了烧结温度对材料热电性能的影响,结果表明在低于300℃的烧结温区,样品室温下的热电性能随烧结温度的升高不断提高,功率因子(α2σ)由未烧结样品的0.59μWcm-1K-2升高到在300℃下烧结样品的15.9μWcm-1K-2,这一结果对确定材料的最佳烧结温度具有重要意义.

The powders of p-type pseudo-ternary Sb2Te3-Bi2Te3-Sb2Se3 thermoelectric materials prepared by mechanical alloying method were analysed by XRD, with Te, Bi, Sb and Se element granules alloyed after 100h ball milling. The alloyed powders were analysed by SEM, showing granules of fine powders about 10--100nm in size. Blocks of p-type pseudo-ternary thermoelectric materials were prepared with the powders by cold-pressing and sintering, Seebeck coefficient and electrical conductivity for samples with different sintering temperatures were measured at room temperature. The results suggest that thermoelectric properties gradually improve with sintering temperatures during 300℃, the power factor enhances from 0.59μW cm^-1K^-2 of unsintered samples to 15.9μW cm^-1K^-2 of samples sintered at 300℃. So the result might play an important role in optimizing sintering temperature.