Pb-Sb-Te三元合金相图500℃等温截面的实验测定  

Isothermal section of Pb-Sb-Te ternary system at 500 ℃

作　　者：徐飞飞[1] 陈玉雯 王媚 陈红梅[1] 陶小马[1] 欧阳义芳[1] 

机构地区：[1]广西大学物理科学与工程技术学院,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2017年第5期1730-1735,共6页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(51201039;11464001;51661003);广西自然科学基金资助项目(2014GXNSFAA118308)

摘　　要：为了获得在PbTe基热电材料中掺杂Sb后的相关系,文中对Pb-Sb-Te三元系500℃等温截面进行了实验测定及相关系的分析研究。采用XRD、SEM及能谱仪对合金样品进行了测试分析,研究结果表明:Pb-Sb-Te三元合金体系500℃等温截面由5个单相区、4个两相区和5个三相区组成。其中,5个三相区分别是PbTe+Sb+δ,PbTe+δ+SbTe,PbTe+Sb2Te3+Te,PbTe+Pb+Sb和PbTe+Sb2Te3+SbTe;在500℃时,Sb元素在PbTe相中的固溶度为2.03at.%,Pb在Sb2Te3相中的固溶度较高,达到7.17at.%;此外,在500℃下Pb-Sb-Te三元合金系中并未出现文献报道的Pb2Sb6Te11三元相。原因可能是Pb2Sb6Te11是一种亚稳态相,其性质不稳定,只可稳定存在于855K(≈580℃)的这个温度点,而本研究测定的是Pb-Sb-Te三元系合金在500℃下的等温截面,与580℃有偏差,Pb2Sb6Te11可能已分解为PbTe和Sb2Te3相,因此没有观察到Pb2Sb6Te11相的存在。In order to obtain phase relationship of Sb doped PbTe based thermoelectric material. The isothermal section of the Pb-Sb-Te ternary system at 500 ℃ was determined and analysed. The alloy samples were investigated by X-ray diffraction analysis （XRD）, scanning electron microscope （SEM） and energy-dispersive X-ray spectroscopy （EDS） techniques. The results show that the isothermal section of the Pb-Sb-Te system at 500 ℃ is composed of five single-phase regions, four two-phase regions and five three-phase regions. Among them, the five three-phase regions are PbTe ＋Sb＋δ, PbTe＋δ＋SbTe, PbTe＋Sb2Te3＋Te, PbTe＋Pb＋Sb and PbTe＋Sb2Te3＋SbTe, respectively. The solubility of Sb in PbTe phase is 2.03 at. % at 500 ℃, and the solubility of Pb in Sb2Te3 is up to 7.17 at. %. Moreover, the Pb2Sb6Tell ternary compound wasn＇t observed in present work. The reason may be that Pb2Sb6Tenis a kind of metastable phase, which is not stable and only exists at the temperature of the 855 K （580 ℃ ）. The experiment in this work was designed to determine the isothermal section of Pb-Sb-Te ternary system at 500 ℃. Compared with the situation at 580 ℃, Pb2Sb6Te11 may have broken down into PbTe and Sb2Te3at 500 ℃, so Pb2Sb6Ten phase was not observed.

关 键 词：Pb-Sb-Te 合金相图 等温截面 

分 类 号：O792[理学—晶体学]