Skutterudite (CoSb3) thermoelectric nanomaterials fabricated by Pulse Plasma in Liquid. (2018)

• Record Type: Journal Article
• Authors: Zybała, Rafał; Schmidt, Maksymilian; Kamińska, Paulina; Kruszewski, Mirosław Jakub; Grzonka, Justyna; Pietrzak, Katarzyna; Ciupiński, Łukasz
• Is Part Of: Materials today. Volume 5:Number 4(2018)Part 1
• Page Start: 10316
• Page End: 10322
• Publication Date: 2018
• Subjects: Thermoelectric materials -- Skutterudite -- Nanomaterials -- Energy harvesting -- Pulse Plasma in Liquid -- Spark Plasma Sintering; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2017.12.279
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: In this work, we present a new fabrication method of thermoelectric nanomaterials using Pulsed Plasma in Liquid (PPL) with a low-energy spark discharge. Thermoelectric (TE) materials can be used for direct energy conversion from heat into electricity. They are of particular interest as a result of enabling both clean energy transformation and waste heat energy harvesting. The efficiency of the conversion process depends on the Carnot cycle and the material's properties, described by the thermoelectric figure-of-merit ( ZT ). This parameter is based on electrical conductivity, Seebeck coefficient and thermal conductivity. One can increase the ZT value by reducing the thermal conductivity e.g. through the nano-structuring of TE materials and, at the same time, conserving their electrical properties. CoSb3, which is a state-of-the-art TE material from the skutterudite family known as a narrow-band gap semiconductor with a parabolic bottom of the conduction band, was studied in the present work. Binary skutterudite CoSb3 polycrystalline ingots were synthesized by a direct fusion technique from pure elements. The densified materials with a cylindrical shape were used as substrates in the fabrication process of CoSb3 nanoparticles via the modified Pulse Plasma in Liquid method. The nanopowders were consolidated using rapid Spark Plasma Sintering (SPS) with the processing time in minutes. X-ray diffraction (XRD), scanning electron microscopy (SEM/EDS) and scanning transmission electron microscopy (STEM) were used to characterize the synthesized powders and sinters. Thermal conductivity was determined by the laser flash technique (LFA). Electrical properties such as resistivity and Seebeck coefficient were measured by the four probe technique, as a function of temperature.