Electronic, Structural, Optical, and Magnetic Characteristics A₂MgS₄ of (A=Dy, Er) Spinel Sulfides: A Density Functional Theory Study

Abstract

Density functional theory (DFT) simulations are performed to explore the physical features of Dy2MgS4 and Er2MgS4. Local density approximation with Hubbard potential (LDA + U) functional is utilized to examine the magnetic and electronic features. Half metallic ferromagnetic (HMF) behavior is confirmed by the spin‐resolved density of states (DOS) and band structure (BS) plots. Spin‐resolved BS and DOS show that Dy2MgS4 and Er2MgS4 for spin‐down are metallic, whereas both compounds in spin‐up show semiconductor nature with the bandgaps of 1.731 and 3.081 eV for Dy2MgS4 and Er2MgS4, correspondingly. Both compounds also feature exchange energies and crystal field splitting, indicating the magnetic characteristics. The estimated magnetic moments of X2MgS4 (X = Dy, Er) are 20μB and 12μB, correspondingly, also revealed by spin‐polarized magnetic density. Optical properties such as refractive index n(ω), absorption coefficient α(ω), dielectric constant , reflectivity R(, extinction coefficient k(ω), and optical conductivity σ(ω) are also explored. The optical bandgaps for MgX2S4 (X = Dy, Er) are 1.70 and 1.51 eV, respectively; it shows that both are transparent to visible light. Results indicate that both materials can be suitable for spintronic and solar‐cell usage.

Comprehensive DFT investigation of X2MgSe4 (X = Dy, Tm) spinels for opto-spintronic and thermoelectric devices

“…The enthalpy of formation (ΔH) i.e., the energy required to disrupt the bonds between solid atoms in a material, was computed at absolute zero temperature to assess the thermodynamically stable configuration of X 2 MgSe 4 (X = Dy, Tm) spinel selenides. A negative value of ΔH denotes a stronger atomic bond that is advantageous for the long-term viability of spinels and it is calculated by utilizing the following the equation [9,20]…”

“…Nazar et al proved semiconductor (SC) nature of both Dy 2 MgS 4 and Er 2 MgS 4 with E g of 1.731 and 3.081 eV, respectively, through spin polarized density of states. The magnetic moments of X 2 MgS 4 (X = Dy, Er) were estimated as 20 and 12 μ B , respectively per unit cell [9]. Alburaih et al utilized the WIEN2k code to investigate the physical characteristics of chalcogenide spinel compounds CdEr 2 S 4 and CdEr 2 Se 4 .…”

Semi‐Metallic Superionic Layers Suppressing Voltage Fading of Li‐Rich Layered Oxide Towards Superior‐Stable Li‐Ion Batteries

“…Density of state for pristine LMO (LMO‐p) and LMO with oxygen vacancies (LMO‐OVs) are plotted in Figure 6a and b, respectively. The metallic properties of LMO‐p differ from the semi‐metallic character of LMO‐OVs, which have a non‐zero band gap of Fermi energy (E F ) in the spin down state but a band gap in the spin up state [42] . The generates sporadic spin‐polarized conducting electrons in the spin down state of LMO‐OVs at the E F are prone to forming bonded states, which is advantageous in preventing the release of oxygen [13] .…”

“…The metallic properties of LMO-p differ from the semi-metallic character of LMO-OVs, which have a non-zero band gap of Fermi energy (E F ) in the spin down state but a band gap in the spin up state. [42] The generates sporadic spin-polarized conducting electrons in the spin down state of LMO-OVs at the E F are prone to forming bonded states, which is advantageous in preventing the release of oxygen. [13] The presence of oxygen vacancies in LMO-OVs significantly impacts the electron spin of both manganese and oxygen, as evident from the results of charge density investigation, which is shown in Figure 6c and e by slicing the crystal plane at the red lines in Figure 6d and f.…”

Investigations of the structural, mechanical and optoelectronic attributes of Rb2BB'Tl I6 ( B'= As, Ga) double perovskites for photovoltaics

“…In the rst Brillouin zone, a dense mesh consisting of 1500K points is selected. Furthermore, the optical characteristics are evaluated using the Kramer-Kronig complex equations [45].…”