Peculiarities of thermoelectric half-Heusler phase formation in Gd-Ni-Sb and Lu-Ni-Sb ternary systems

Effect of secondary LuNiSn phase on thermoelectric properties of half-Heusler alloy LuNiSb

“…The lattice parameters derived for LuNiSn are in good agreement with the literature data [28,29]. For the two prepared alloys of LuNiSb, the lattice parameter aHH is slightly smaller than the values reported in the literature [20,21], and it is somewhat sample-dependent. Remarkably, for the composite sample, the lattice parameters are different than those of the constituent compounds.…”

Modeling of structural and energetic parameters of р-Er1-xScxNiSb semiconductor

“…Semi-Heusler phases RNiSb (R is a rare earth metal) and solid solutions based on them with a structure of the MgAgAs type proved to be promising in the direction of searching for new thermoelectric materials. The study of p-RNiSb semiconductors (R -Sc, Y, Gd, Er, Lu) established a defectivity in their crystal structure [1][2][3][4][5], and in Refs. [3,6] on the example of p-LuNiSb a variant of occupancy of the crystallographic positions in the unit cell was proposed: Ni(4c) = 92.65 % Ni + 1.35 % Lu + 6 % Vac; Lu(4a) = 100 % Lu; Sb(4b) = 100 % Sb.…”

Electronic Structure and Thermoelectric Performance of Narrow‐Gap GdNiSb Half Heusler Compound: Density Functional Calculations

“…studied at 873 K by Romaka et al [26] using X-ray and metallographic analyses in the whole concentration range where the deviation from the perfect stoichiometry of GdNiSb and LuNiSb is observed. The electronic structure of the GdNiSb compound was calculated by Wei et al [29] Results showed the metallic character of GdNiSb in the high-temperature phase whereas in the low-temperature phase GdNiSb was a semiconductor.…”

“…[ 16 ] The TE properties of ScCoSb and ScNiSb compounds were observed by Morozkin et al [ 17 ] They observed that the Seebeck coefficients increased from 2.1 to 2.9 μV K −1 with increasing temperature from 240 up to 380 K. Harmening et al [ 18 ] observed the defects in HH‐type antimonides ScTSb (T = Ni, Pd, and Pt). Recently, large number of studies on the TE properties of rare earth‐based HH compounds have been reported [ 19–25 ] but work on gadolinium (Gd)‐based HH compounds [ 26–28 ] for TE performance is less explored. The phase equilibria in Gd–Ni–Sb and Lu–Ni–Sb ternary systems were studied at 873 K by Romaka et al [ 26 ] using X‐ray and metallographic analyses in the whole concentration range where the deviation from the perfect stoichiometry of GdNiSb and LuNiSb is observed.…”

“…Recently, large number of studies on the TE properties of rare earth‐based HH compounds have been reported [ 19–25 ] but work on gadolinium (Gd)‐based HH compounds [ 26–28 ] for TE performance is less explored. The phase equilibria in Gd–Ni–Sb and Lu–Ni–Sb ternary systems were studied at 873 K by Romaka et al [ 26 ] using X‐ray and metallographic analyses in the whole concentration range where the deviation from the perfect stoichiometry of GdNiSb and LuNiSb is observed. The electronic structure of the GdNiSb compound was calculated by Wei et al [ 29 ] Results showed the metallic character of GdNiSb in the high‐temperature phase whereas in the low‐temperature phase GdNiSb was a semiconductor.…”