Structure, microstructure and thermoelectric properties of germanite-type Cu22Fe8Ge4S32 compounds

Abstract

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. The final version has undergone significant change prior to publication, especially 2 references from this PDF file have been removed.

Crystal Structure Classification of Copper‐Based Sulfides as a Tool for the Design of Inorganic Functional Materials

“…These findings demonstrate the importance of interstitial cations in every complex copper sulfide exhibiting astructure derived from an ordered sphalerite-type arrangement. Promising performances have also been reported in other families belonging to group B, such as talnakhite Cu 17.6 Fe 17.6 S 32 ,w ith a ZT of 0.23 at 625 K, [65] germanite Cu 22 Fe 8 Ge 4 S 32 with a ZT of 0.27 at 700 K, [120] stannoidite Cu 8 Fe 3 Sn 2 S 12 with a ZT of 0.35 at 630 K, [74] and a ZT predicted to reach around 0.5 at 800 Kfor doped mawsonite Cu 6 Fe 2 SnS 8 . [112] Interestingly,t alnakhite and renierite,t wo phases structurally closely related to group Ac halcopyrite and group Bg ermanite,r espectively, both exhibit very low lattice thermal conductivities as aresult of their complex crystal structures (Figure 9, Tables 1and 2).…”

Promoted crystallisation and cationic ordering in thermoelectric Cu26V2Sn6S32 colusite by eccentric vibratory ball milling

“…The mechanochemistry seems to be the most effective, low-cost, and eco-friendly approach towards scalable synthesis of Cu-based sulphides. 38,39 This has been recently demonstrated on ternary and quaternary copper sulphides, such as tetrahedrite Cu12Sb4S13, [40][41][42][43][44] Cu4Sn7S16, 32 bornite Cu5FeS4, 24,25 colusite Cu26V2Sn6S32, 16,20,34,36,45,46 germanite derivative Cu22Fe8Ge4S32, 21,47,48 stannoidite Cu8Fe3Sn2S12, 22 isocubanite CuFe2S3, 28 mohite Cu2SnS3, 49,50 stannite Cu2FeSnS4, 51…”

Long-Range Cationic Order Collapse Triggered by S/Cl Mixed-Anion Occupancy Yields Enhanced Thermoelectric Properties in Cu5Sn2S7

“…The past few years have witnessed a resurgence of popularity for ternary and quaternary copper sulfides as potential thermoelectric materials. , Unlike binary copper sulfides, no evidence for performance degradation triggered by ionic conductivity has been reported in these multicomponent systems. − In the absence of ionic conductivity, the dimensionless thermoelectric figure of merit ZT = S 2 T /κρ (where T is the absolute temperature, S is the Seebeck coefficient or thermopower, ρ is the electrical resistivity, and κ is the total thermal conductivity) characterizes the efficiency by which these compounds convert thermal into electrical energy or vice versa. Significant attention, in the class of copper sulfides, was initially devoted to mineral tetrahedrites, which exhibit ZT values over unity around 700 K. ,− Such renewed interest for thermoelectric copper sulfides has led to the detailed investigation of many other promising complex sulfides, including bornite Cu 5 FeS 4 , , stannoidite Cu 8 Fe 3 Sn 2 S 12 , germanite derivatives Cu 22 Fe 8 Ge 4 S 32 , − kesterite Cu 2 ZnSnS 4 , , Cu 4 Sn 7 S 16 , , chalcopyrite CuFeS 2 , colusite Cu 26 T 2 M 6 S 32 ( T = Ti, V, Nb, Ta, Cr, Mo, W; M = Ge, Sn, Sb), − and mohite Cu 2 SnS 3 . − …”