No abstract

By optimizing the concentration of the substitutional defect PrMg1, Mg3.2Pr0.02Sb1.5Bi0.5 exhibits a peak zT value of 1.70 at 725 K.

N-type MgSb-based Zintl compounds are proved to be high-performance thermoelectric materials with multiple degenerate valleys and low lattice thermal conductivity. Here, we investigate the electronic band structure and the thermoelectric properties of n-type MgSb using first-principles density functional theory. A high ZT of 3.1 at 725 K is obtained when the minimum lattice thermal conductivity and the optimal carrier concentration are reached. The calculated thermoelectric performance demonstrates that MgSb possesses an isotropic character in thermoelectric transport. Furthermore, the calculated lattice thermal conductivity κ reveals that the unusually low κ in MgSb predominantly originates from the large Grüneisen parameter γ.