First-principles study of electronic and thermoelectric properties of Zr_1-xHf_xNiPb (x=0.12) compound

The first-principles calculation has been performed to study the electronic and thermoelectric transport properties of Zr_1-xHf_xNiPb (x=0.12) compound using full potential linearized augmented plane wave (FPLAPW) method based on Density functional theory (DFT) as implemented in WIEN2k. The optimized value of lattice parameter is in excellent agreement with available data. Various thermoelectric properties such as Seebeck coefficient, electrical conductivity, Power factor and electronic thermal conductivity are studied in wide range of temperature from 100-1000 K. The value of electrical conductivity increases from 0.025x10²⁰Scm^-1sec^-1 for ZrNiPb to 0.036x10²⁰Scm⁻¹sec^-1(x=0.12) at room temperature on Hf substitution. There is a small variation of power factor from 1.56x10¹¹WK⁻²cm^-1sec^-1(x=0) to 1.62x10¹¹WK⁻²cm⁻¹sec^-1 (x=0.12) at room temperature. The Hf substitution also decreases the thermal conductivity, which is favorable condition to obtain large value of figure of merit ZT. The increase in the value of power factor and decrease in the value of thermal conductivity show that Hf doped ZrNiPb acts as good thermoelectric material.