Reaction mechanism and thermoelectric properties of In0·22Co4Sb12 prepared by magnesiothermy. (June 2020)

• Record Type: Journal Article
• Authors: Le Tonquesse, S.; Alleno, É.; Demange, V.; Prestipino, C.; Rouleau, O.; Pasturel, M.
• Is Part Of: Materials today chemistry. Volume 16(2020)
• Publication Date: 2020-06
• Subjects: Skutterudites -- Magnesioreduction synthesis -- Rietveld phase quantification -- Thermal conductivity; Chemistry -- Periodicals; Materials -- Research -- Periodicals; Materials science -- Periodicals; Chemistry; Materials -- Research; Electronic journals; Periodicals; 660.282
• DOI: 10.1016/j.mtchem.2019.100223
• Languages: English
• ISSNs: 2468-5194

Abstract

Abstract: The magnesioreduction synthesis of In0·22 Co4 Sb12 with high In rattler concentration from Sb2 O4 and In-doped Co3 O4 precursors is reported. This process directly yields a submicronic powder in a single step of 96 h at 810 K. The reaction mechanism has been investigated by stopping the reaction every 12 h and quantifying the existing phases by X-ray diffraction and Rietveld refinements. The precursors are first reduced in CoO and Sb2 O3 lower oxides, then form CoSb2 O6 and CoSb2 O4 intermediates which are finally reduced in In x Co4 Sb12 . A powder with 350 nm average size and mostly composed of In-filled skutterudite phase with composition close to In0·17 Co4 Sb12 is obtained. Upon spark plasma sintering, small residual amount of InSb reacts with the skutterudite matrix to form a single-phase densified pellet with composition close to In0·22 Co4 Sb12 . The resulting densified material with 1.8 μm average grain size shows a figure of merit ZT max of 0.95 at 750 K. Graphical abstract: Image 1