Importance of two current model in understanding the electronic transport behavior of inverse Heusler alloy: Fe 2 CoSi

Here we explore the applicability of the two current model in understanding the transport behavior of Fe 2 CoSi compound by using the first principles calculations in combination with the Boltzmann transport theory. The spin-unpolarized calculation shows large density of states (DOS) at Fermi level (E F) and is unable to provide the correct temperature dependence of transport coefficients. The spin-polarised calculation shows reduced DOS at the E F in the spin-up channel, whereas spin-dn channel have almost zero DOS at the E F . The absolute value of Seebeck coefficient in the spin-up channel shows linear increment with the temperature and in the spin-dn channel it varies non-linearly. The electrical conductivity also shows non-linear temperature dependence in both the spin channels whereas, the electronic thermal conductivity shows linear temperature dependence. The values of transport coefficients and their temperature dependence obtained by using the two current model are found to be in fairly good agreement with the experimental data. Present work clearly suggests the importance of two current model in understanding the transport properties of the compound.