First principle investigations of electronic, ferromagnetic, and thermoelectric aspects of chalcogenides BeCe2X4 (X = S, Se, Te) for spintronics

The rare earth spinel's chalcogenides are emerging aspirants for spintronic technology in which the spin of electrons controls the storage and transfer of electronic data. Therefore, this article elaborates on the electronic, magnetic, and transport behaviors of Ce-doped spinel's chalcogenides BeCe₂X₄ (X = S, Se, Te). The preliminary evaluations of energy release during optimization confirm the ferromagnetic states are more stable than paramagnetic, antiferromagnetic states. The formation energy further consolidates their thermodynamic stability. The Heisenberg model evaluates the Curie temperature, and the complete spin polarization of electrons is determined by spin polarization density calculations at the Fermi level. The density of states and band structures show the Half-metallic ferromagnetism. Furthermore, the role of the exchange mechanism of electrons in ferromagnetism has been addressed by exchange energies and exchange constants that arise due to p-states of chalcogenides ions (S, Se, Te) and f-states of Ce. The distribution of the magnetic moments of Ce to nonmagnetic elements (Be, X) and interstitial positions of structures is secured ferromagnetism by exchanging electrons and avoiding Ce ions' clustering. Finally, the thermoelectric behavior and its impact on electron spin for these materials are also elaborated briefly. The low lattice thermal conductivity increases their importance for reliable spintronic devices.