The rare earth‐based half Heusler GdNiSb compound is investigated theoretically for electronic and thermoelectric (TE) performance. The most efficient method to treat the rare earth metals, Coulomb‐corrected local spin density approximation (LSDA + U), is used. The calculated total density of states (DOS) of GdNiSb shows that the maximum contribution near Fermi energy (E_F) is due to the spin‐up/down Ni‐3d and spin‐down Gd‐4f states. A narrow energy gap of 0.279 eV is opened which is consistent with other reported values. TE properties are investigated using classical transport theory. The total Seebeck coefficient (S) increases linearly with temperature and attains a maximum value of 80 μV K⁻¹ at 800 K. The S value of 60 μV K⁻¹ at 380 K is in good agreement with the experimental value, 58 μV K⁻¹, at the same temperature. The maximum value of the power factor (P) is as high as 825 × 10⁹W m⁻¹ K⁻² s⁻¹ at 650 K in the spin‐down channel. The TE figure of merit (ZT) reaches the maximum value of ≈0.475 at 800 K in the spin‐down configuration. All the values of the TE parameters of GdNiSb indicate a good candidate for TE applications.

中文翻译：

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窄间隙GdNiSb半霍斯勒化合物的电子结构和热电性能：密度泛函计算

理论上研究了基于稀土的半赫斯勒GdNiSb化合物的电子和热电（TE）性能。使用最有效的稀土金属处理方法是库仑校正的局部自旋密度近似（LSDA +  U）。计算得出的GdNiSb的总态密度（DOS）表明，接近费米能量（E _F）的最大贡献是由于自旋升/降Ni-3d和自旋降Gd-4f态。打开了0.279 eV的窄能隙，这与其他报告的值一致。使用经典的运输理论研究TE的性质。总塞贝克系数（S）随着温度线性增加，并且在800 K时达到最大值80μVK ^-1。小号60μV的K值^-1在380 K是与实验值，58μVķ吻合^-1，在相同的温度。在降速通道中，在650 K时，功率因数（P）的最大值高达825×10 ⁹ W m ^-1  K ^-2  s ^-1。在降速配置中，TE的品质因数（ZT）在800 K时达到约0.475的最大值。GdNiSb的TE参数的所有值都表明是TE应用的良好候选者。