Characterization of Dielectric Properties of Graphene and Graphite Using the Resonant Cavity in 5G Test Band

Abstract

This paper presents a study about the dielectric constant r e , dielectric loss tangent tan ( ) g d and effective electrical conductivity e

Modulation of Electrokinetic Potentials Using Graphene-Based Surfaces and Variable Substrate Charge Density

“…Here, the ion size and surface roughness-related effects on electrokinetic flows − are outside the scope of our investigations since the focus of our study is on microscale channels of length scales much larger than ion/molecule size. Then, in the continuum approximation, a 0.3 nm (/1.5 nm) thickness for the SLG (/FLG) along with an ε graphene of ∼9 was assumed, − with corresponding surface charge densities of 30 and 9 mC/m 2 , respectively. ,, The continuity of the electrical displacement (the product of the dielectric permittivity with the potential gradient) across the electrolyte–graphene interface was taken as a constraint. With the assumed continuity of the electrical displacement and a linear potential profile, the electrical potential at the electrolyte–graphene interface was expressed through the relation: − ε e ∂ φ false( z false) ∂ z | z = 0 = σ s + ε g φ s − φ | z = 0 λ G Here, ε e and ε g are the relative permittivity of electrolyte (∼79) and graphene (∼9), respectively, σ s is the total surface charge density on the graphene surface, φ s and φ| z =0 represent the potential of the substrate and potential at the electrolyte–graphene interface, and λ G is the graphene layer thickness.…”

A Gate‐Tunable Ambipolar Quantum Phase Transition in a Topological Excitonic Insulator

“…A BZ 4 = 0.46 Å −2 are areas of BZ and truncated BZ in the k • p calculations, 𝜉 = 25 nm is the screening length, and Ω = 21.6 Å 2 is the unit cell area of WTe 2 . The effective dielectric constant ϵ, can be estimated as ϵ = (ϵ 1 + 1)/2 = 5.2, [53] where ϵ 1 = 9.3 for graphene substrate [54,55]…”

“…The strength of screened Coulomb interactions in the long wavelength limit U 0 = U ( q ≈ 0) in the 2D heterostructure can be approximated as $$U_0 = \frac{A_{kp}e^2\xi}{4A_{BZ}\epsilon \epsilon _0\Omega}$$, [ 19 ] where $$A_{BZ}=\frac{4\pi ^2}{ab}=1.83$$ Å −2 and $$A_{kp}=\frac{A_{BZ}}{4}=0.46$$ Å −2 are areas of BZ and truncated BZ in the k · p calculations, ξ = 25 nm is the screening length, and Ω = 21.6 Å 2 is the unit cell area of WTe 2 . The effective dielectric constant ϵ, can be estimated as ϵ = (ϵ 1 + 1)/2 = 5.2, [ 53 ] where ϵ 1 = 9.3 for graphene substrate [ 54,55 ] and ϵ 2 = 1 for the vacuum above. The above estimate yields U 0 = 25.2 eV in excellent agreement with the U 0 = 25 eV as assumed in this model.…”

Investigating Thermal Conductivity in Graphene Nanocomposites

“…Graphene electron it become a role of zero-bandgap material called Dirac point reason for conduction and valance bond direct connected to each other [4,5,6]. In some previous years, have more expectation in terahertz science and technology, wide band of research areas such a long distance communication, wireless, medical devices, weather predictions and geological sciences etc.…”