Electronegative guests in CoSb₃

Abstract

Electronegative guests filled into CoSb3yield a unique “cluster vibration” that provides a new perspective on designing novel inclusion compounds.

Defect-Controlled Electronic Structure and Phase Stability in Thermoelectric Skutterudite CoSb3

“…38 This explains the extremely low thermal conductivity in S+Te doped CoSb 3 as observed in the previous experiment reports. 17 Similarly, as shown in Figure 3(f), the presence of Se i +Te Sb breaks the Te-3Sb fourmembered ring, and a new covalent Se−Sb bond is generated with the length of 2.808 Å in the Se i +Te Sb structure. This value is consistence with the radii (~ 2.777 Å) between Se and Sb in Sb 2 Se 3 .…”

“…The optimized Co 4 Sb 11.5 Te 0.5 had a zT value of 0.72 at 850 K. 24 However, Co 4 Sb 11.5 Te 0.5 synthesized through a high pressure method followed by SPS had a α σ 3 maximum zT value of 1.15 at 883 K. 18 17 The calculated electron carrier concentration of Te doping is higher compared with that of Se and S doping. The predicted phase diagram shows that S has a larger solubility within CoSb 3-y Te y system than that in the system without Te doping.…”

“…[15][16][17]43 However, the breakage of etc., might lead to a similar structure shown in Figure 3(c) and can potentially improve the TE properties of CoSb 3 further. We believe this work provides a new defect-engineering strategy to determine the electronic structure and phase stability in doped CoSb 3 , which could be applied to other TE and non-TE energy materials with open structures.…”

“…is the density of states of ideal host cell, and is the Fermi-Dirac distribution given by: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 13 (8) Following the procedure described above, the Fermi level (E F ) and free carriers can be determined by iteratively solving the overall charge neutrality requirement, as displayed in 17 The annealing temperature region of CoSb 3 is generally around 850 -1100 K. [14][15][16][17][18][19][20][21][22][23] The electron carrier concentration is found to be The total composition x of a phase with defects within an equilibrium set of atomic chemical potentials can be calculated by:…”

“…15 Very recently, CoSb 3 filled with electronegative atoms (S and Se) were successfully prepared with a strong covalent guest-host interactions between S (or Se) and Sb, which leads to very low lattice thermal conductivity. 17 The second approach is substituting Co or Sb atoms with metals or semimetals to tune the electronic properties, [17][18][19][20][21][22][23] and lots of experimental studies show VIA-group element (O, S, Se, Te) dopants can significantly influence the TE properties of CoSb 3 . 17,18,[24][25][26][27] For Te doped CoSb 3 , Te substituting Sb (Te Sb ) would be the dominant point defect.…”