Thermoelectric and Mechanical Properties of Spark Plasma Extruded Bismuth and Antimony Chalcogenide Based Solid SolutionsстатьяИсследовательская статья
Аннотация:This work demonstrates the good promise of the spark plasma extrusion method for the production of bismuth and antimony chalcogenide based low-temperature thermoelectric materials. Bi2Te2.85Se0.15 and Bi0.4Sb1.6Te3 solid solutions with n- and p-type conductivities, respectively, have been synthesized. The phase composition and structure of the synthesized solid solutions have been studied using X-ray diffraction and scanning and transmission electron microscopy methods. The thermoelectric properties of the materials have been measured using Harman’s method. The mechanical properties have been studied by measuring the ultimate compression strength.It has been demonstrated that spark plasma extrusion produces a sharp axial texture in the Bi0.4Sb1.6Te3 and Bi2Te2.85Se0.15 solid solutions. However, despite the presence of the texture, the specimens synthesized using the spark plasma extrusion method prove to have good mechanical strength. The p- and n-type conductivity materials have shown room-temperature ultimate uniaxial compression strengths of 200 and 250 MPa, respectively.Due to the formation of an anisotropic structure as a result of current pulse application during spark plasma extrusion, the synthesized Bi0.4Sb1.6Te3 and Bi2Te2.85Se0.15 solid solutions have shown high thermoelectric figure of merit, i.e., ZT = 1.03 at 320 K for the p-type conductivity material and ZT = 0.95 at 340 K for the n-type conductivity material.
