Thermoelectric properties of half-metallic FeMnScGa using first principle calculation

Abstract

Here, we have investigated the electronic structure and thermoelectric properties of FeMnScGa alloy by combined use of full potential linearized augmented plane-wave (FP-LAPW) method and Boltzmann transport theory implemented in Wien2K and BoltzTraP code, respectively. Using the TB-mBJ potential, half-metallic nature is clearly observed with appearance of energy band gap value ∼0.41 eV for the minority charge carriers. Transport coefficients in 200-1000 K temperature range are estimated under the constant relaxation time approximations (with assumption of τ=10−14 s). Total contribution to the Seebeck coefficients of this alloy from up and dn-spin channels are computed by using two-current model. The calculated values of Seebeck coefficients are found to be negative in the entire temperature region under present study, which suggests the n-type characteristic of this alloy. The magnitude of Seebeck coefficient is found to be increasing with temperature and exhibit the large value∼-87 µV/K in 700-1000 K temperature range. Total electrical conductivity value is found to be ∼2.0×105 Ω−1m−1 at 1000 K. The present study shows, with half-metallic electronic structure, FeMnScGa possess a good behavior to be considered it as a thermoelectric material. With experimental verification in future, it can be used for thermoelectric application in high temperature region.