Structural, elastic, thermodynamic, electronic, optical and thermoelectric properties of MgLu2X4 (X= S, Se) spinel compounds from ab-initio calculations

Engineering of Hydrogenated (6,0) Single-Walled Carbon Nanotube under Applied Uniaxial Stress: A DFT-1/2 and Molecular Dynamics Study

“…The real part ϵ 1 (ω) characterizes the degree of polarization under an external electric field, and the imaginary part ϵ 2 (ω) characterizes the interband electronic transition from occupied states to unoccupied states. , ϵ 2 (ω) can be directly calculated from the one-electron orbitals and energies obtained from the Kohn–Sham equations. It is given by the equation below , ε 2 false( ω false) = ℏ 2 e 2 π m 2 ω 2 ∑ n n ′ ∫ k d 3 k false| < k ⇀ n false| p⃗ | k ⇀ n ′ > | 2 false[ 1 − f ( k ⇀ n ) false] δ false( E k ⇀ n − E k ⇀ n false′ − normalℏ ω false) where …”

“…The real part ϵ 1 (ω) characterizes the degree of polarization under an external electric field, and the imaginary part ϵ 2 (ω) characterizes the interband electronic transition from occupied states to unoccupied states. , ϵ 2 (ω) can be directly calculated from the one-electron orbitals and energies obtained from the Kohn–Sham equations. It is given by the equation below , where is the momentum operator, is the eigenfunction of the eigenvalue, and is the Fermi Distribution function. The real part of the dielectric function is obtained by the Kramers–Kronig transformation from its corresponding imaginary part as …”

“… 87 , 88 ϵ 2 (ω) can be directly calculated from the one-electron orbitals and energies obtained from the Kohn–Sham equations. It is given by the equation below 89 , 90 where is the momentum operator, is the eigenfunction of the eigenvalue, and is the Fermi Distribution function. The real part of the dielectric function is obtained by the Kramers–Kronig transformation from its corresponding imaginary part as …”

A theoretical investigation of the lead‐free double perovskites halides Rb2XCl6 (X = Se, Ti) for optoelectronic and thermoelectric applications

“…A solid that exhibits a Poisson's ratio between 0.25 and 0.50 is stabilized by a central force. In contrast, a solid that has a Poisson's ratio outside of this range is stabilized by a non‐central force 61,62 . Since the Poisson ratios of Rb 2 SeCl 6 and Rb 2 TiCl 6 are 0.248 and 0.272, respectively, it is clear that Rb 2 SeCl 6 crystal is a non‐central force solid and Rb 2 TiCl 6 crystal is a central force solid.…”

Structural, Elastic, Electronic, Magnetic, and Thermoelectric Characteristics of MgEu2X4 (X = S, Se) Spinel Compounds: Ab‐Initio Calculations

“…Also, nanoparticles of spinel ferrite have received considerable attention among researchers due to their widespread technological applications such as magnetic resonance imaging (MRI) contrast agent, drug‐delivery, magnetically recoverable efficient photo‐catalyst, gas sensor, hyperthermia cancer treatment, magnetic refrigeration (MR), anode material for Li‐ion battery, magnetic recording media with higher storage density, microwave devices, spintronic devices, super‐capacitors, paint industry, water splitting for hydrogen production, etc. [ 5,7 ] Idrissi et al recently studied the physical properties of NiFe 2 O 4 [ 8 ] and ZnFe 2 O 4 [ 9 ] spinels using density functional theory (DFT), Monte Carlo simulation, and mean‐field theory. They found that NiFe 2 O 4 spinel shows a second‐order ferromagnetic‐paramagnetic phase transition around T c = 844 K and this result is in good agreement with the experiment.…”