Theoretical study of rare earth in the spinels chalcogenide MgCe2Z4 (Z = S, Se) for spintronic and thermo-electric applications

Abstract

For leading spintronic technology, the significance of rare earth in the spinels chalcogenide MgCe2Z4 (Z = S, Se) has been investigated. Wein2K and BoltzTraP program packages are used to calculate the magnetic and transport characteristics of the spinels. While comparing the energies within the ferromagnetic and nonmagnetic states, the ferromagnetic state stability in the ground state is examined. The formation energy, phonon dispersion curve, and mechanical stability conditions help clarify the issue of stability in the cubic ferromagnetic phase. Poisson's and Pugh's ratios are employed to ensure the brittle characteristics. To explore the electronic properties, modified Becke and Johnson (mBJ) potential are utilized to investigate both spinels' direct narrow bandgap (spin up channel) nature. Chalcogenide's 2p produces the total magnetic moments- and rare-earth metals' f-states, which result in significant hybridization around the Fermi level. The computed total magnetic moment integer values and polarization are used to demonstrate spin polarisation. Finally, the Seebeck coefficient, thermal-to-electrical conductivity ratio, and power factor are used to evaluate thermoelectric properties.