A potential full Heusler thermoelectric material CO2ZrZ (Z=Al, Si, Ga and Sn) in low temperature: An Ab-initio investigation

The structural, electronic, magnetic, elastic and thermoelectric properties of full-Heusler alloys Co(2)ZrZ (Z = Al, Si, Ga and Sn) are investigated using the augmented plane wave method (FP-LAPW) based on the framework of spin density functional theory. The term of the exchange and correlation potential (XC), is treated by the generalized gradient approximation GGA and Trans-Blaha-modified Becke-Johnson (TB-mBJ). The results obtained showed that the Cu2MnAl-type structure has more stable energy than the Hg2CuTi-type structure for all the full-Heusler studied. From electronic calculations, it is found that all the compounds studied have an indirect band gap with a half-metallic behavior. Furthermore, we also found that all materials have integral magnetic moments which are mainly due to 100% spin polarization at Fermi energy. The calculated elastic constants and the anisotropy shear factors indicate that these compounds have a ductile character and are mechanically stable. Finally, we calculated the thermoelectric properties by applying Boltzmann theory as implemented in the BoltzTraP code. The results obtained for the merit factor (ZT) and Seebeck coefficient (S) make these materials promising candidates in thermoelectric applications and in spintronics devices.

Automated summary

The structural, electronic, magnetic, elastic, and thermoelectric properties of full-Heusler alloys Co(2)ZrZ (Z = Al, Si, Ga, and Sn) were investigated using the framework of spin density functional theory. The results showed that the Cu2MnAl-type structure is more stable and exhibits half-metallic behavior with 100% spin polarization at Fermi energy. These alloys also display good mechanical stability and show promise for thermoelectric applications and spintronics devices.