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This paper presents an analysis of the Hamiltonian formulation for continuous systems with second-order derivatives derived from Dirac's theory. This approach offers a unique perspective on the equations of motion compared to the traditional Euler–Lagrange formulation. Focusing on Podolsky's generalized electrodynamics, the Hamiltonian and corresponding equations of motion are derived. The findings demonstrate that both Hamiltonian and Euler–Lagrange formulations yield equivalent results. This study highlights the Hamiltonian approach as a valuable alternative for understanding the dynamics of second-order systems, validated through a specific application within generalized electrodynamics. The novelty of the research lies in developing advanced theoretical models through Hamiltonian formalism for continuous systems with second-order derivatives. The research employs an alternative method to the Euler–Lagrange formulas by applying Dirac's theory to study the generalized Podolsky electrodynamics, contributing to a better understanding of complex continuous systems. [ABSTRACT FROM AUTHOR]

A promising strategy for detecting lung cancer requires determining its biomarkers in a patient's exhaled breath. Acetone has been identified as an important biomarker in the cases of lung cancer. Two-dimensional materials show characteristics such as excellent sensitivity, resistance to high temperatures, and stability which are essential for their effective use in gas-sensing applications. In this work, we investigated acetone adsorption on the pristine and transition metal (TM)-doped (Fe, Co, Ni, Cu, and Zn) C3B monolayers with the density functional theory calculations. We found that the Zn-doped C3B shows a larger adsorption energy value among designed monolayers. The change of band gap energy of surfaces after acetone adsorption is obtained between 29% and 200%. Besides, results show that acetone has a quick recovery at room temperature. The work function variation of studied monolayers upon acetone adsorption has also been investigated and results show that TM-doped C3B systems are sensitive to acetone gas molecules. This work suggests that the C3B-based layers can be used as a biosensor to identify volatile organic compound biomarkers such as acetone. [ABSTRACT FROM AUTHOR]

Investigating novel compounds has become necessary due to the need for sophisticated materials in optoelectronic devices and spintronics. Because of their unique properties, magnesium-based spinels MgSm2X4 (X = S and Se) are very promising for these applications. We used the spin-polarized PBEsol for structural properties and the PBEsol functional for mechanical behavior, both using the WIEN2k code. Both compounds' stability in the magnetic and non-magnetic phases was validated by the Birch-Murnaghan equation of state, and their stability in the cubic phase was verified by the Born stability criterion. Their ductile character was shown by the computation of Pugh's ratio and Poisson ratio. Both MgSm2S4 and MgSm2Se4 display metallic behavior in the spin-up channel and semiconducting behavior in the spin-down channel, indicating a half-metallic nature, according to TB-mBJ potential calculations. With total magnetic moments of 20 μB, both materials showed ferromagnetic properties. Samarium ions contributed 5.27 μB for MgSm2S4 and 5.34 μB for MgSm2Se4. Furthermore, we computed optical parameters in the energy range of 0 to 15 eV, such as absorption, extinction coefficient, reflectivity, dielectric function, and refractive index. Our results demonstrate the potential of MgSm2X4 spinels for future technological developments by revealing their prospective optoelectronic and spintronic applications. [ABSTRACT FROM AUTHOR]

Due to their stability, eco-friendly nature, lack of lead, and high performance, double perovskites are promising materials for solar cells, thermoelectric generators, and renewable energy applications. This study investigates the structural, dynamical, elastic, and optoelectronic properties of Cs2TlGaX6 (X = Cl, F) compounds using first-principles calculations with the WIEN2k code. While the PBE-GGA method accurately predicts ground state properties, it underestimates band gaps. To address this, the TB-mBJ approach, known for precise semiconductor bandgap calculations, was used. Calculated formation energy confirmed the thermodynamic stability of both compounds, with Cs2TlGaF6 (-2.81 eV) more stable than Cs2TlGaCl6 (-1.79 eV). Imaginary frequencies absence indicates phonon stability. Structural optimization plots reveal stable unit cell configurations, and elastic property analysis confirms their ductile nature and resistance to cracking. Cs2TlGaCl6 behaves as an indirect wide band gap semiconductor (3.78 eV), suitable for various applications, while Cs2TlGaF6 exhibits insulating behavior with a larger band gap (6.23 eV). Optical properties were also calculated, suggesting potential applications in optoelectronics, photonics, and semiconductors within the ultraviolet energy ranges. [ABSTRACT FROM AUTHOR]

Double perovskites are promising for solar cells, thermoelectric generators, and renewable energy due to their stability, eco-friendly nature, lack of lead, and high performance. This study uses first-principles calculations to examine the structural, dynamical, elastic, and optoelectronic properties of Ba₂PrXO₆ (X = Ir, Pt) with WIEN2k code. The ferromagnetic (FM) state is more stable than the non-magnetic (NM) state for both compounds, with Ba₂PrIrO₆ having formation energy of − 1.354 being slightly more stable than Ba₂PrPtO₆ with formation energy of − 1.258. Both compounds are dynamically and mechanically stable with C11 values of 305 for Ba2PrIrO6 and 322 for Ba2PrPtO6, ductile, anisotropic, resistant to plastic deformation, and exhibit ionic bonding and central force crystal characteristics. Electronic band structure calculations reveal that Ba₂PrIrO₆ behaves as a metal in both spin channels with PBE but shows direct bandgap semiconductor behavior for the spin-down channel (1.51 eV) with PBE-mBJ. Ba₂PrPtO₆ is identified as an indirect bandgap semiconductor by both methods. Both compounds show significant electronic transitions in the UV spectrum, indicating potential for UV absorption applications. [ABSTRACT FROM AUTHOR]

In the present work, we investigate the structural, elastic, optical, and electronic properties of Ba2MBiO6 (M = Sm, Tb) oxide double perovskites, using Density Functional Theory within the Wien2k The generalized gradient approximation GGA for structural and elastic properties while the Tran-Blaha modified Becke-Johnson Tb-mBJ is employed for both optical and electrical properties. The Birch-Murnaghan equations of state and tolerance factors are used to verify the structural stability of both compounds. It is determined that both systems are elastically stable and have anisotropic ductile and ionic bonding behavior. The Ba2SmBiO6 is a non-central force crystal ν = 0.51 as with Ba2TbBiO6 a central force crystal ν = 0.29. Finally, as a potential candidate for spintronic applications, Ba2SmBiO6 shows half-metallic behavior exhibiting spin-dependent band gaps. Ba2TbBiO6 behaves as a direct band gap semiconductor with a 1.79 eV band gap. Both compounds have optical properties in the UV-visible region, indicating potential for optoelectronic applications. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical investigation utilizing the full-potential linearized augmented planewave method (FP-LAPW) within density functional theory (DFT) framework, implemented in the Wien2k program. Analysis reveals that Sr2DySbO6 (t = 0.991) and Sr2LaSbO6 (t = 1.01) exhibit theoretical tolerance factors suggesting their crystallization in a face-centered cubic form (FCC) with space group (Fm3m; No. 225). Notably, Sr2DySbO6 demonstrates a slightly higher stability (χ_ value of 2.1207) compared to Sr2LaSbO6 (χ_ value of 1.9902). Both compounds also show negative formation energies, suggesting that they are feasible for experimental synthesis and structurally stable. Stability is further confirmed by structural optimization by atomic relaxation and total energy reduction against unit cell volume. Both compounds exhibit ductility, anisotropy, ionic bonding nature, elastic stability, resistance to plastic deformation, and central force crystal properties. Sr2DySbO6 electronic characteristics reveals that it is metallic, whereas Sr2LaSbO6 is insulating. Energy-wise, optical properties are assessed between 0 and 15 eV. Both the compounds have demonstrated noteworthy UV responses are making use of the unique characteristics and high energy of UV light for a range of creative uses. Overall, these findings advocate for experimental exploration of these compounds, hinting at potential applications. [ABSTRACT FROM AUTHOR]

Investigating novel compounds has become necessary due to the need for sophisticated materials in optoelectronic devices and spintronics. Because of their unique properties, magnesium-based spinels MgSm2X4 (X = S and Se) are very promising for these applications. We used the spin-polarized PBEsol for structural properties and the PBEsol functional for mechanical behavior, both using the WIEN2k code. Both compounds' stability in the magnetic and non-magnetic phases was validated by the Birch-Murnaghan equation of state, and their stability in the cubic phase was verified by the Born stability criterion. Their ductile character was shown by the computation of Pugh's ratio and Poisson ratio. Both MgSm2S4 and MgSm2Se4 display metallic behavior in the spin-up channel and semiconducting behavior in the spin-down channel, indicating a half-metallic nature, according to TB-mBJ potential calculations. With total magnetic moments of 20 μB, both materials showed ferromagnetic properties. Samarium ions contributed 5.27 μB for MgSm2S4 and 5.34 μB for MgSm2Se4. Furthermore, we computed optical parameters in the energy range of 0 to 15 eV, such as absorption, extinction coefficient, reflectivity, dielectric function, and refractive index. Our results demonstrate the potential of MgSm2X4 spinels for future technological developments by revealing their prospective optoelectronic and spintronic applications., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Rahman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)