Mechanical, half-metallic ferro-magnetic and thermoelectric properties double perovskites Li

Electron spin has improved numerous electronic applications, including quantum computing and data storage. The present research used density functional theory (DFT) within the FP-LAPW system implemented in WIEN2k to comprehensively examine the structural, electrical, magnetic, mechanical, and thermoelectric characteristics of halide double perovskites Li2W(Cl/Br)6. The PBE-sol functional along with the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential is used for precise bandgap calculations while the transport behavior is analyzed with the help of BoltzTraP program. Li2W(Cl/Br)6 crystallize in a stable cubic Fm3̅m state, as evidenced by negative formation energies (− 2.98 and − 2.05 eV for Li2WCl6 and Li2WBr6, respectively) and also with the verification of Born stability conditions. The computed Curie values of 426 K (Li2WCl6) and 394 K (Li2WBr6) demonstrate strong ferromagnetism at ambient temperature. Mechanical investigation suggests ductile response, with Pugh’s ratios more than 1.75 and anisotropy factors less than unity. Electronic band analysis reveals half-metallic properties, including full spin polarization at the Fermi level, caused by p-d and s-d orbital hybridizations in W-site octahedra. Ferromagnetic moments are mostly provided by W d-states, which reinforces strong ferromagnetic coupling. The total magnetic moment of 2µB in Li2W(Cl/Br)6 exhibit strong exchange splitting along with half metallic behavior. Thermoelectric examination shows encouraging transport behavior, with higher Seebeck coefficients and power factors at higher temperatures. Li2W(Cl/Br)6 double perovskites have half-metallic and thermoelectric characteristics, making them suitable for spintronic and energy conversion applications.