Effect of High Pressure and Temperature on Structural, Thermodynamic and Thermoelectric Properties of Quaternary CoFeCrAl Alloy

Abstract

Employing first-principles based on density functional theory we have investigated the structural, magneto-electronic, thermoelectric and thermodynamic properties of quaternary Heusler alloy CoFeCrAl. Electronic band structure displays that CoFeCrAl is an indirect band gap semiconductor in spin-down state with the band gap value of 0.65 eV. Elastic constants reveal CoFeCrAl is a mechanically stable structure having a Debye temperature of 648 K along with a high melting temperature (2130 K). The thermoelectric properties in the temperature range 50-800 K have been calculated. CoFeCrAl possesses a high Seebeck coefficient of − 46 μV/K at room temperature along with the huge power factor of ∼ 4.8 (1012 μW cm−1 K−2 s−1) which maximizes the figure-of-merit up to ∼ 0.75 at 800 K temperature and suggesting CoFeCrAl as potential thermoelectric material. The effect of high pressure and high temperature on the thermal expansion, Gruneisen parameter and heat capacity were also studied by using the quasi-harmonic Debye model.