Eur. Phys. J. Plus (2021) 136: 568
https://doi.org/10.1140/epjp/s13360-021-01554-1

Regular Article

Spin-based transport properties of Cs₂WX₆ (X = Cl, Br) ferromagnets for spin-injected thermoelectric current

¹ Department of Physics, Government Post Graduate Jahanzeb College Saidu Sharif, Swat 19130, Khyber Pakhtunkhwa, Pakistan
² Department of Chemistry, College of Science, King Saud University, P.O. Box 22452, 11495, Riyadh, Saudi Arabia
³ Department of Physics, Faculty of Science, Taibah University, Medina, Saudi Arabia
⁴ Materials Modeling Lab, Department of Physics, Islamia College Peshawar, 25120, Khyber Pakhtunkhwa, Pakistan
⁵ Department of Mathematics and Natural Sciences, Prince Mohammad Bin Fahd University, P. O. Box 1664, 31952, Alkhobar, Kingdom of Saudi Arabia

^a azmatupesh@gmail.com

Received: 9 July 2020
Accepted: 10 May 2021
Published online: 21 May 2021

Abstract

The conversion of waste heat into electrical energy by spin Seebeck effect (SSE) can be a proficient alternative of traditional thermoelectrics. For this purpose, most efficient materials are required. In this article, we report Cs₂WX₆ (X = Cl, Br) ferromagnetic materials for possible SSE on the basis of results of first principles calculations combined by density functional and classical Boltzmann transport theories. The synthesis possibility of both the compounds is verified from negative values of formation energy, while the cubic phase stability is evaluated through calculated values of tolerance factor. The ductile elastic nature is confirmed from Cauchy pressure and Pugh’s condition. The lattice thermal conductivity calculated through Slack’s equation is observed to decrease with rise in temperature. Electronically, both Cs₂WX₆ compounds are predicted as half metallic through density of states, band structure and integral values of magnetic moments (2 µ_B). Moreover, from spin-dependent thermoelectric properties, large values Seebeck coefficients and figure of merit are observed in spin-down states in comparison of spin-up channel. The spin-dependent thermoelectric parameters along with half metallic character make Cs₂WX₆ compounds suitable for spin Seebeck effect.