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The present research article reports the thermoelectric properties of the Weyl semi-metal 'ZrTe' by employing density functional theory in combination with the semi-classical Boltzmann transport theory. The thermo-electric parameters such as Seebeck coefficient, electrical conductivity, electronic as well as lattice thermal conductivity are evaluated and the variation in these parameters via a change in temperature, chemical potential as well as the change in doping concentration of 'ZrTe' are also computed. The calculated values of lattice thermal conductivity decrease with the increase in temperature values; this factor favors the thermoelectric response of the Weyl semi-metal 'ZrTe'. As the calculated highest peaks of the Seebeck coefficient concerning the change in doping concentration lies in the negative region, which determines that 'ZrTe' is an 'n-type' thermoelectric material. [ABSTRACT FROM AUTHOR]

: In the present work we explore the electronic, vibrational and thermoelectric properties of new Li based quaternary Heusler compound LiYNiSn that is recently proposed by Jiangang He et.al. [Chem. Mater. 30 (2018) 4978] which is based on the 18-electron rule. Here the theoretical calculations are performed within the approach of density functional theory and semi classical Boltzmann transport equations with the constant relaxation time approximation. The band gap of the proposed compound is 0.38 eV that is in agreement with the available results in literature. The Seebeck coefficient and the Figure of Merit (ZT) are calculated at the three different temperatures (300K, 600K and 700K) with respect to the chemical potential (μ). The maximum ZT recorded is 0.14 at 700 K temperature. The compound is reported first time as the thermoelectric material and can be beneficial in the experimental research of thermoelectrical materials. [ABSTRACT FROM AUTHOR]

In this report, we have investigated the structural and lattice dynamical properties of Half Heusler alloys RuMnX (X=P, As) under the framework of first principles calculations. The structural parameters such as lattice constants have been calculated and found to be in good agreement with the available theoretical results, while bulk modulus and pressure derivative of bulk modulus has been reported for the first time. A linear response approach of density functional perturbation theory has been employed for the calculations of lattice dynamics of these alloys. The calculated phonon dispersion curve (PDC) does not show any imaginary frequency in any symmetric directions, indicating the stability of alloys in the cubic phase. All the phonon frequencies corresponding to acoustical and optical phonon modes have been assigned. Comparison of PDC of both alloys reveal that the phonon gap has been found to be more in RuMnAs than in RuMnP. Lattice dynamical properties for these alloys has been reported for the first time. The phonon density of states for both alloys have also been calculated. Keywords: Half Heusler alloy, Crystal Structure, Lattice Dynamics, Phonons. [ABSTRACT FROM AUTHOR]