PbTe热电材料的合金化研究

Alloying Investigation of PbTe Thermoelectric Materials

[目的]探索PbTe热电材料的合金化方法。[方法]利用机械合金化方法和高频熔炼方法快速制备PbTe热电材料。首先,通过调整Pb和Te成分配比,球磨时间,制备出品质较好的PbTe热电材料;其次,利用高频熔炼的方法制备PbTe材料;最后对所制备的样品进行X射线衍射(XRD)和扫描电镜(SEM)测试和分析,比较两种方法制备样品的优缺点。[结果]机械合金化制备的PbTe样品退火时,细化的晶粒开始回复和再结晶,结晶度明显增加,但是仍然低于高频熔炼的样品,且退火后,块状PbTe材料中存在大量的缺陷和晶格的畸变。[结论]通过机械合金化制备的PbTe样品结晶度明显低于高频炉制备的样品。

[Objective]Alloying methods were explored for PbTe thermoelectric materials.[Methods]High energy mechanical ball milling method and high frequency melting method were used to prepare PbTe thermoelectric materials.Firstly,the fractions of the samples and the milling time were adjusted to obtain the high quality samples.Secondly,the high frequency melting method was used to prepare the PbTe samples.Finally,the X-ray diffraction (XRD) and scanning electron microscope (SEM)were employed to obtain the crystal information and micro-morphology.[Results]The crystallinity of the PbTe prepared by mechanical alloying was obviously lower than that of high frequency melting.After annealing,the crystallinity of me-chanical alloying was also lower than that of high frequency melting,but the crystallinity of mechanical alloying was increased during the annealing.The annealed bulk PbTe had lots of de-fects and lattice distortion.[Conclusion]The crystallinity of the PbTe prepared by mechanical alloying was obviously lower than that of high frequency melting.