真空熔炼及热压烧结Sb_2Se_3热电材料的微结构研究

Microstructure of Sb_2Se_3 Thermoelectric Material Prepared by Vacuum Melting and Hot-pressing

采用石英管真空封装高纯度的Sb粉和Se粉,在800℃下熔炼8h,冷却后制成Sb2Se3粉末,在真空下进行热压烧结(470℃,60 MPa)并保温0.5 h,制备出Sb2Se3块体材料。运用XRD、SEM和EDS法对材料物相、形貌和成分进行了表征。结果表明,真空熔炼合成粉末和热压烧结块体材料的XRD图谱与Sb2Se3的标准衍射图谱(01-072-1184)相对应;Sb2Se3热压块体材料在平行和垂直于热压方向的断面上都分布着大量的层片状结构,平行于热压方向的断面上层片状结构沿某一方向择优生长,而在垂直于热压方向的断面上层片状结构分布更均匀,结晶更充分;材料中Sb和Se的原子百分比分别为40.68%、59.32%,接近于2∶3。

High pure Sb and Se sealed in a vacuum quartz tube were smelted at 800℃ for 8 h. Sb2Se3 powders were fabricated by grinding the ingot. Sb2Se3 bulk materials were prepared by hot-press sintering at 470℃ under 60 MPa for 0.5 h in vacuum. The phase structure and microscopic topography of the samples were characterized by XRD and SEM. The results show that the diffraction peaks of powders alloyed and bulk materials by hot-press sintering mainly corresponding to the standard Sb2Se3 reference code （01-072-1184）. The bulk samples of Sb2Se3 by hot-press sintering have a plenty of sheet layer structures on the cross section perpendicularing and paralleling the hot-press direction. Preferentially, the oriented sheet layer structures were obtained on the cross section paralleling to the hot-press direction. However, the sheet layer structures on the cross section perpendicularing to the hot-press direction distributes more homogeneously and has fully crystallization than that on the cross section paralleling to the hot-press direction. The atomic percentage of element Sb and Se is 40.68% and 59.32% respectively, approaching to 2 ： 3.