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In this study, the WIEN2k code, utilizing the full potential linearized augmented plane wave (FPLAPW) approach within the framework of density functional theory (DFT), explicitly employing the PBEsol approximation, is employed to investigate the fundamental properties of W-doped and (Mo, W) co-doped cubic CeO2. Herein, lattice constants, bulk modulus and cell volumes were evaluated for structural properties. The total density of states (TDOS) for various doped and co-doped CeO2 systems was used to explain the origin of magnetic behavior. The band structure (BS) calculations show that the doped and co-doped materials exhibit semiconductor behavior with a direct bandgap in both spin channels. The calculated total spin magnetic moments of W/CeO2 and (Mo, W)/CeO2 alloys are 2.002 μ B and 4.007 μ B , respectively. Furthermore, the optical absorption shows absorption peaks in the visible range and a redshift. As a result, adding molybdenum and tungsten additives improves the electro-optical properties of previous materials. [ABSTRACT FROM AUTHOR]

This study analyzes how adding europium and transition metals (Cu, Ag, and Au) at a 12.5% concentration to magnesium oxide (MgO) affects its physical characteristics and potential uses. To do so, the full potential linearized augmented plane wave (FP-LAPW) method, based on spin-polarized density functional theory (SP-DFT), is used to derive the results. Wu and Cohen's generalized gradient approximation (GGA-WC) described the exchange-correlation potential. The modified Becke-Johnson exchange potential (TB-mBJ) was also used to improve the findings of optoelectronic properties. When Eu and TM (Cu, Ag, and Au) impurities are co-doped into the nonmagnetic (NM) semiconductor MgO, the structural optimization results show that the lattice constants increase, and the bulk modulus decreases with increasing the atomic number of transition metals. The resulting dilute magnetic oxides (DMOs) are stable in the spin-polarized ferromagnetic (FM) phase, and the formation energy values confirm their stability in the F m 3 ̄ m cubic structure, with the lowest value belonging to Eu 0. 1 2 5 TM 0. 1 2 5 Mg 0. 7 5 0 O. Similarly, calculations of electronic properties using the WC-mBJ functional demonstrate that all compounds have an indirect half-metallic bandgap at L- Γ equal to 2.53, 2.49, and 1.39 eV for Eu 0. 1 2 5 Cu 0. 1 2 5 Mg 0. 7 5 0 O, Eu 0. 1 2 5 Ag 0. 1 2 5 Mg 0. 7 5 0 O, and Eu 0. 1 2 5 Au 0. 1 2 5 Mg 0. 7 5 0 O, respectively. They have an integer magnetic moment of 6 μ B . The density of states shows that at the Fermi level, the 4f-Eu, d-TM, and p-O states give rise to new energy levels. This indicates that the f–p–d hybridization provides this system with its FM properties. Also, these compounds' dielectric function and absorption spectra are calculated and analyzed to learn more about their optical properties. The results provide insight into the optical behavior of the materials. It is observed that the co-doped compounds exhibit greater optical absorbance than their un-doped MgO counterparts do. This theoretical investigation opens the way to preparing high magnetic moment DMOs using TM and rare earth as dopants suitable for spintronic and UV devices. [ABSTRACT FROM AUTHOR]

In this study, the fundamental properties of silver-doped CeO2 forming the compounds Ce1−xAgxO2 [x = 3.125% (SC), 6.25% (BCC), and 12.5% (FCC)] were investigated using the full-potential linearized augmented plane wave FP-LAPW method based on spin-polarized density functional theory SP-DFT, as introduced in the Wien2k package. The calculations were carried out by adopting the revised Perdew–Burke–Ernzerh solid PBE-sol approach. The obtained findings from structural parameters show a decrease of both bulk modulus and lattice constants with increasing the concentrations. Meanwhile, the electronic properties, such as spin-polarized electronic band structures and density of states analysis of both spin channels, illustrate semiconductor ferromagnetic nature for doped compounds at all concentrations. Furthermore, the optical features, including energy absorption spectra and also the real and imaginary parts of the dielectric function, are investigated. These results reveal that Ce1−xAgxO2 (x = 3.125%, 6.25%, and 12.5%) possesses better optical absorbance than pure CeO2. From the above-mentioned results, it appears that the silver-doped CeO2 seems to be a promising candidate for spintronic and photocatalytic areas. [ABSTRACT FROM AUTHOR]