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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.Graphical abstract
This paper presents the structural, electronic, and magnetic properties of pure and Nb doped MgO, in its zinc blende and rock salt phase for small concentration. In our work, the full potential linearized augmented plane wave plus local orbital (FP-LAPW + lo) method, implemented in the WIEN2K simulation package and the Local Density Approximation (LDA) were employed. The results obtained show that pure MgO has a gap of 4.97 eV and Mg0.875Nb0.125O has a metallic character. The modifications in the band gap and magnetic properties of magnesium oxide mainly originate from the 4 d-orbitals of the Nb atoms. In comparison with Mg and O atoms (0.007 and 0.054), the magnetic data shows that the Niobium magnetic moment (1.3528 µβ) is the dominant one. As a result, the total magnetic moment of our component is equals to 2.9091 µβ. We consider that MgO and Mg0.875Nb0.125O could be promising candidates for electronic systems and related fields.
The overall aim of this study is to investigate theoretically the structural, electronic, and magnetic properties of calcium sulfide (CaS) doped with chromium (Cr) impurity, in order to conduct a new search dilute magnetic semiconductors (DMS) suitable for different applications in electronics and spintronics. For measuring, the physical property of this compound is implemented using the first principles approach employed in WIEN2K code. The structural characteristics are optimized using the Generalized Gradient Approximation established by Perdew-Burk-Ernzerhof (PBE-GGA). We calculate and minimize the total energy of the three ternary compounds (Ca0.75Cr0.25S, Ca0.50Cr0.50S, and Ca0.25Cr0.75S) in the paramagnetic (PM), ferromagnetic (FM), and antiferromagnetic (AFM) phase. We find all compounds stable in (FM) structure, whereas the modified Becke and Johnson local density approximation (mBJ-LDA) functional has been employed to evaluate the electronic and magnetic properties. Based on our findings, indicate that this system revealed a half-metallic ferromagnetic behavior with half-metallic gap (HM) and 100% spin-polarized at the fermi level for all chromium (Cr) concentrations. This advantageous set of properties is due to the half-metallic behavior, where the majority spin and minority spin exhibit metallic and semiconducting behaviors respectively. The chromium atom is the most important source of the total magnetic moment in these compounds (4 μβ) by comparison with magnetic moments produced by Ca and S atoms, which have minor contribution. Finally, our prediction results require an experimental confirmation in the future.
The objective of this study is to theoretically investigate the electronic, structural and magnetic properties of calcium sulfide (CaS) doped with transition metal vanadium (V) at various concentrations of this element in the rock-salt phase. All properties of Ca1−xVxS compounds are achieved using the full potential linearized augmented plane wave (FP-LAPW) method with a density functional theory (DFT) implemented in WIEN2 K code. The results obtained show that the Ca0.75V0.25S and the Ca0.50V0.50S compounds are of half-metallic ferromagnetic (HMF) character at a 100% spin polarization, which makes them potential candidates for spin injection applications in spintronic devices, while the Ca0.25V0.75S compound depicted a nearly half-metallic character. In all compounds, the data of the magnetic moment demonstrated that the vanadium impurity atom (3 μB) is the most important source by comparison with the Ca and S, which have minor contributions. In addition, the half-metallic gap (GHM) is an important parameter to consider for potential applications in spintronic devices, which are 0.916 eV and 0.315 eV, respectively, for Ca0.75V0.25S and Ca0.50V0.50S compounds, while for x = 0.75, it is destroyed due to the broadening of 3d states of vanadium impurity in the gap. However, an experimental confirmation is needed to confirm our predictions.