Rapid Preparation of Co1-xMxSb3 (M = Fe, Mn) Skutterudites two series filling: Enabling high-efficiency thermoelectric

Abstract

Abstract The skutterudite, of general formula CoSb3 is a thermoelectric material with high mobility, large atomic mass, and high electrical conductivity. As the Seebeck coefficient is more than 100 µVK-1, coupled with a thermal conductivity is around 10 Wm-1K-1 using Fe and Mn doping, it provides a pathway for the attainment of improved Figure of Merit. Fe and Mn with stoichiometric fractions x = 0, 0.05, 0.1, and 0.15 are expected to decrease thermal conductivity and increase electrical conductivities through the skutterudite's Phonon Glass Electron Crystal (PGEC) structure. Skutterudites of formulation Co1-xMxSb3 (M = Fe, Mn) were synthesized using the modified polyol method, and the materials were characterized using XRD, SEM-EDX, FTIR, Raman, and I-V meters. The particle size of the Co1-xMxSb3 ranged from 21.06–32.24 nm, and the cell unit volume was 743.5-746.2 Å3. Furthermore, adding Fe and Mn doping changed the local crystal structure. The SEM analysis showed that the grains were agglomerated, while the mapping of Co, Fe, Mn, and Sb indicated that these elements were evenly distributed on the surface. FTIR functional group analysis at wave numbers ~ 418–424 cm-1 exhibited Co-Fe and Co-Mn bonds, while Co-Sb bonds were detected at ~ 406–410 cm-1. The concentration of charge carriers and electrical conductivity from the Raman and I-V meters increased with the stoichiometric doping fraction. The electrical conductivity obtained ranges from 103-105 Ω-1.cm-1, which implies that Co1-xMxSb3 is a semiconductor material with the potential for thermoelectric applications.