scholarly journals Magnetic Field Effect of Near-Field Radiative Heat Transfer for SiC Nanowires/Plates

2018 ◽  
Vol 8 (11) ◽  
pp. 2023
Author(s):  
Zhiyuan Shen ◽  
Hao Wu ◽  
Han Wang
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Field Intensity ◽  
Effective Medium Theory ◽  
Near Field ◽  
Magnetic Field Effect ◽  
Medium Theory ◽  
Sic Nanowires ◽  
Magneto Optical Effect ◽  
Field Radiation

The SiC micro/nano-scale structure has advantages for enhancing nonreciprocal absorptance for photovoltaic use due to the magneto optical effect. In this work, we demonstrate the near-field radiative transfer between two aligned SiC nanowires/plates under different magnetic field intensities, in which Lorentz-Drude equations of the dielectric constant tensor are proposed to describe the dielectric constant as a magnetic field applied on the SiC structure. The magnetic field strength is qualified in this study. Using local effective medium theory and the fluctuation-dissipation theorem, we evaluate the near-field radiation between SiC nanowires with different filling ratios and gap distances under an external magnetic field. Compared to the near-field heat flux between two SiC plates, the one between SiC nanowires can be enhanced with magnetic field intensity, a high filling ratio, and a small gap distance. The electric field intensity is also presented for understanding light coupling, propagation, and absorption nature of SiC grating under variable incidence angles and magnetic field strengths. This relative study is useful for thermal radiative design in optical instruments.

Application Conditions of Effective Medium Theory in Near-Field Radiative Heat Transfer Between Multilayered Metamaterials

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
X. L. Liu ◽  
T. J. Bright ◽  
Z. M. Zhang
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Effective Medium Theory ◽  
Near Field ◽  
Effective Medium ◽  
Medium Theory ◽  
Metal Metal ◽  
Doped Silicon ◽  
Silicon And Germanium

This work addresses the validity of the local effective medium theory (EMT) in predicting the near-field radiative heat transfer between multilayered metamaterials, separated by a vacuum gap. Doped silicon and germanium are used to form the metallodielectric superlattice. Different configurations are considered by setting the layers adjacent to the vacuum spacer as metal–metal (MM), metal–dielectric (MD), or dielectric–dielectric (DD) (where M refers to metallic doped silicon and D refers to dielectric germanium). The calculation is based on fluctuational electrodynamics using the Green's function formulation. The cutoff wave vectors for surface plasmon polaritons (SPPs) and hyperbolic modes are evaluated. Combining the Bloch theory with the cutoff wave vector, the application condition of EMT in predicting near-field radiative heat transfer is presented quantitatively and is verified by exact calculations based on the multilayer formulation.

STUDY OF THE OPTICAL ABSORPTION OF Cu CLUSTERS IN THE Cu/ZnO SYSTEM

2001 ◽  
Vol 15 (17n19) ◽  
pp. 625-629 ◽  
Author(s):  
O. VAZQUEZ-CUCHILLO ◽  
A. BAUTISTA-HERNANDEZ ◽  
U. PAL ◽  
L. MEZA-MONTES
Keyword(s):  
Dielectric Constant ◽  
Optical Absorption ◽  
Free Path ◽  
Absorption Spectra ◽  
Effective Medium Theory ◽  
Composite Films ◽  
Mean Free Path ◽  
Optical Absorption Spectra ◽  
Medium Theory ◽  
Coated Nanoparticles

Optical absorption of Cu/ZnO composite films grown by r.f. sputtering are presented. We calculated the optical absorption spectra based on a colloidal-copper model with mean-free-path (MFP) and size corrections to the bulk dielectric constant. All effective-medium theory is used to analyze the presence of the coated nanoparticles and the ZnO matrix. The parameters of the model are fitted to reproduce the experimental spectra.

Dielectric Properties of Glass Capillary Arrays

1998 ◽  
Vol 511 ◽  
Author(s):  
T. E. Huber ◽  
Leo Silber ◽  
Frank Boccuzzi
Keyword(s):  
Dielectric Constant ◽  
Effective Medium Theory ◽  
Far Infrared ◽  
Soda Lime ◽  
Index Of Refraction ◽  
Soda Lime Glass ◽  
Frequency Range ◽  
Glass Capillary ◽  
Medium Theory ◽  
X Band

ABSTRACTGlass Capillary Arrays (GCA) are low density columnar monolithic structures made of soda-lime glass. This structure, in which 76% of volume between the columns, the channels, is void, also has a greatly reduced dielectric constant in comparison with bulk glass. We have measured the index of refraction and absorption of samples of GCA's in the X-band, 8 × 109 Hz to 1.2×1010 Hz, for various orientations of the channels with respect to the polarization. For channels perpendicular to the polarization direction we have measured an index of refraction of 1.15. In comparison the index of refraction of (bulk) soda-lime glass is 2.6. We also examined the absorption in the far-infrared (FIR) frequency range between 6×1011 Hz and 6×1012 Hz. In this frequency range we obtain a k2 dependence due to losses in the glass matrix at higher frequencies. The results of the X-band and FIR results are interpreted in terms of an effective medium theory of the real and imaginary part of the dielectric constant of the composite.

Effective Medium Theory of Dielectric Constant of Granular Materials in the Presence of Skin Effect

1990 ◽  
Vol 195 ◽  
Author(s):  
L.V. Panina ◽  
A.N. Lagar´kov ◽  
A. Ќ Sarychev ◽  
Y.R. Smychkovich ◽  
A.P. Vinogradov
Keyword(s):  
Dielectric Constant ◽  
Composite Material ◽  
Percolation Threshold ◽  
Granular Materials ◽  
Skin Effect ◽  
Effective Medium Theory ◽  
Critical Concentration ◽  
Medium Theory ◽  
Composite Systems ◽  
Conducting Component

We consider the behavior of the dielectric constant of percolation composite systems. An example of such systems is a composite material consisting of a disordered mixture of metallic and insulating particles. A reduction in concentration P of the metallic (conducting) component reduces the static conductivity of the composite, so that it vanishes at some critical concentration PC known as the percolation threshold.

Retrieval of Uniaxial Permittivity and Permeability for the Study of Near-Field Radiative Transport Between Metallic Nanowire Arrays

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Jui-Yung Chang ◽  
Payam Sabbaghi ◽  
Yu-Shao Weng ◽  
Yu-Bin Chen ◽  
Liping Wang
Keyword(s):  
Magnetic Permeability ◽  
Effective Medium Theory ◽  
Near Field ◽  
Nanowire Arrays ◽  
Radiative Properties ◽  
Electric Permittivity ◽  
Medium Theory ◽  
Wave Interference ◽  
Guided Mode ◽  
Magnetic Resonances

Abstract Recently metamaterials made of periodic nanowire arrays, multilayers, and grating structures have been studied for near-field thermal radiation with enhanced coupling of evanescent waves due to surface plasmon/phonon polariton, hyperbolic mode, epsilon-near-zero and epsilon-near-pole (ENP) modes, guided mode, and wave interference. In this work, both effective uniaxial electric permittivity and magnetic permeability of a nanowire-based metamaterial are retrieved theoretically through the far-field radiative properties obtained by finite difference time-domain (FDTD) simulations. The artificial magnetic response of metamaterials, which cannot be obtained by traditional effective medium theory (EMT) based on electric permittivity of constitutes only, is successfully captured by the nonunity magnetic permeability, whose resonant frequency is verified by an inductor-capacitor model. By incorporating the retrieved electric permittivity and magnetic permeability into fluctuational electrodynamics with multilayer uniaxial wave optics, the near-field radiative heat transfer between the metallic nanowire arrays is theoretically studied and spectral near-field heat enhancements are found for both transverse electric and magnetic waves due to artificial magnetic resonances. The understanding and insights obtained here will facilitate the application of metamaterials in near-field radiative transfer.

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