Analysis of Structural Stability and Half-Metallic Ferromagnetism of Cs2VX6 (X=Cl, Br) Double-Perovskites for Spintronic Applications: Ab-Initio Simulations

Spintronics has become an emerging field based on electronic spin usage for various technological applications. Herein, we explored the ferromagnetic characteristics of novel double-perovskite Cs2VX6 (X=Cl, Br) compounds within the framework of density functional theory. In search of the most stable ground state, we found the ferromagnetic state is at the lowest possible energy state. The structural stability in the cubic phase was assessed from the Goldschmidt tolerance factor, and negative values of formation energies confirmed thermodynamic stability for both compounds. The existence of all positive frequencies in phonon spectra indicates both compounds are thermodynamically stable, and their spin-polarized density of states and band structures revealed the half-metallic ferromagnetism nature. The 100% spin polarization factor and the reasonable magnetic moment values suggest these double-perovskites potential in spintronic applications. Additionally, the thermoelectric response, regarding high power factors suggests these double-perovskites suitability for thermoelectric device applications.