水热合成及等离子活化烧结制备碘掺杂硫化铅热电材料  

Iodine doped Pb S thermoelectric materials prepared by hydrothermal synthesis and plasma activated sintering route

作　　者：杨玉晶[1] 史荣娜 杜学丽[1] Yang Yujing Shi Rongna Du Xueli(Tianjin University of Technology, School of Material Science and Engineering, Tianjin 30038)

机构地区：[1]天津理工大学材料科学与工程学院,天津300384

出　　处：《粉末冶金技术》2016年第5期341-345,共5页Powder Metallurgy Technology

基　　金：大学生创新创业训练计划项目资助(201410060003);天津市应用基础与前沿技术研究计划(15JCYBJC18500)

摘　　要：以乙酸铅(Pb(Ac)_2)、硫代乙酰胺(TAA)和碘化钾(KI)为原料,在120℃水热反应合成出了沿<100>方向六臂星形纳米枝叶结构Pb S+x%(原子分数)PbI_2(x=0,0.5,1,1.5,2,2.5,5)粉末。合成的粉末采用等离子活化烧结(PAS)技术在40 MPa下以60℃/min升温到500℃保温5 min,获得了致密度在90%左右的烧结体,掺杂Pb I2的Pb S烧结试样的XRD峰位左移,表明Pb I2进入Pb S晶格I-占据S2-使晶格膨胀;SEM分析烧结试样断口形貌发现Pb S烧结试样的晶粒尺寸随PbI_2掺杂量增加而增大,相应致密度也随之增加,但是当Pb I2掺杂量大于2%以后,晶粒尺寸及致密度开始下降。Hierarchical six-arm,star-shaped PbS ＋ xmol% PbI_2（ x =0,0. 5,1,1. 5,2,2. 5,5） powders were hydrothermally synthesized at 120 ℃ with lead acetate,thioacetamide（ TAA） and potassium iodide as raw materials. The unique star-shaped Pb S crystals have six symmetric arms along the 〈100〉 directions,each of which shows a dendritic structure and consists of nanoleaflets. The synthesized powders were densified by plasma activated sintering（ PAS） under 40 MPa and heated to 500 ℃in 8 ~10 min,soaked for 5 min. The relative density of sintered samples is about 90%. Compared with Pb S（ x =0）,the main diffraction peaks of sintered Pb S ＋ xmol% PbI_2（ x〉 0） samples shift to lower diffraction angles,indicating the expansion of host lattice,which might be explained from the substitution of S2-by I-. SEM micrographs of the fractured surfaces for Pb S ＋x mol% Pb I2 bulks show that the average grain size increases with x increasing and then decreases as further increasing x above2,which might be resulted from the limited solubility of PbI_2 in Pb S.

关 键 词：PB S热电材料 水热合成 等离子活化烧结 有限固溶 

分 类 号：TQ424.25[化学工程]