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