• Title/Summary/Keyword: scattering layer

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EM wave scattering by bianisotropically coated multilayer cylinder with an impedance sheet[II] (쌍이방성 매질 코팅 다층 원통에 의한 전자파 산란 해석[II])

  • 엄상진;윤중한;이화춘;곽경섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.4B
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    • pp.391-399
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    • 2001
  • In this paper, electromagnetic wave scattering from a bianisotropicaly coated cylinder is formulated by using wave functions for bianisotropic media and boundary-value method. The cross section of the cylinder is made of a conducting core, a lossless dielectric layer which is both electrically magnetically bianisotropic, and a bianisotropic impedance sheet and a different uniaxial bianisotrpic coating. The solutions to arbitrary polarization angles are presented in two-dimensional. This paper presents and exact solution to the problem of scattering by a long composite circular cylinder using the boundary method. The validity of this solution is verified by comparing numerical results with those in literature. The numerical results for various geometrical and electrical parameters on bistatic scattering cross-section are presented.

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Structure Analysis of Liquid Crystal Emulsions Using X-ray Scattering Analysis (X선 산란분석법을 이용한 액정에멀젼 구조분석)

  • Park, So Hyun;Kim, Su Ji;Noh, Min Joo;Lee, Jun Bae;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.42 no.3
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    • pp.297-302
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    • 2016
  • In this study, we prepared liquid crystal emulsions composed of $C_{12-20}$ alkyl glucoside, $C_{14-22}$ alcohol, and behenyl alcohol and performed structure analysis using various analytical equipment. First, as an important characteristic of liquid crystal emulsions, maltese cross patterns and multi-layer structure were observed by a polarized microscope and cryo-SEM. Also, formation of liquid crystal phase was confirmed by DSC and multi-layer lamellar structure having an interlayer spacing approximately $305{\AA}$ was confirmed by small angle x-ray scattering (SAXS). The alkyl chain arrangement formed orthorhombic structure of a lamellar structure of the liquid crystal emulsion was confirmed by wide angle x-ray scattering (WAXS). These results suggest that information on the various physical properties obtained through the research of liquid crystal emulsion structure is expected to be widely used in cosmetics development in the future.

A Study on TE Scattering by a Conductive Strip Grating between Grounded Double Dielectric Layer (접지된 2중 유전체층 사이의 완전도체띠 격자구조에 의한 TE 산란에 관한 연구)

  • Yoon, Uei-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.4
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    • pp.153-158
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    • 2016
  • In this paper, TE(transverse electric) scattering problems by a conductive strip grating between grounded double dielectric layer are analyzed by applying the PMM(point matching method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the conductive boundary condition is applied to analysis of the conductive strip. The numerical results for normalized reflected power are analyzed by according as the width and spacing of conductive strip, the relative permittivity and thickness of the double dielectric layers, and incident angles. The most normalized reflected powers of the sharp variations in minimum values are scattered in direction of the other angles except incident angle. The numerical results for the presented structure of this paper having a grounded double dielectric layer are shown in good agreement compared to those of the existing papers.

A Study on TE Scattering by a Conductive Strip Grating Over a Dielectric Layer (유전체층 위의 완전도체띠 격자구조에 의한 TE 산란에 관한 연구)

  • Yoon, Uei-Joong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4158-4163
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    • 2015
  • In this paper, the solutions of TE(transverse electric) scattering problems by a condutive strip grating over a dielectric layer are analyzed by using the FGMM(fourier galerkin moment method) and PMM(point matching method) known as a numerical method of electromagnetic fileld. The scattered electromagnetic fields are expanded in a series of floguet mode functions, the boundary conditions are applied to obtain the unknown field coefficients, and the conductive boundary condition is used for the relationship between the tangential electric field and the induced surface current density on the strip. The numerical results for the reflected and transmitted power of zeroth mode analyzed by according as the width and spacing of conductive strip, the relative permittivity and thickness of dielectric layer, and incident angles. Generally, according to the relative permittivity of dielectric layer increased, also the normalized reflected power of zeroth mode increased. To examine the accruacy of this paper, the numerical results of FGMM shown in good agreement compared to those of PMM.

Solution of TE Scattering Applying FGMM for Resistive Strip Grating Between a Grounded Double Dielectric Layer (접지된 2중 유전체층 사이의 저항띠 격자에 대해 FGMM을 적용한 TE 산란 해)

  • Uei-Joong Yoon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.3
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    • pp.71-76
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    • 2023
  • In this paper, TE(transverse electric) scattering problems by a resistive strip grating between a grounded double dielectric layer are analyzed by applying the FGMM(fourier galerkin moment method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the resistive boundary condition is applied to analysis of the resistive strip. Overall, as the resistivity decreased, the magnitude of the current density induced in the resistive strip increased, and the reflected power also increased. In case of uniform resistivity, the reflected power decreased as the relative permittivity of the dielectric layers increased or the thickness of the dielectric layer increased. The numerical results for the presented structure in this paper are shown in good agreement compared to those of the existing papers.

Solution of TE Scattering by a Resistive Strip Grating Between a Double Dielectric Layer Using FGMM (FGMM을 이용한 2중 유전체층 사이의 저항띠 격자구조에 의한 TE 산란 해)

  • Uei-Joong Yoon
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.619-624
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    • 2023
  • In this paper, TE(transverse electric) scattering problems by a resistive strip grating between a double dielectric layer are analyzed by using the FGMM(fourier galerkin moment method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the resistive boundary condition is applied to analysis of the resistive strip. In order to deal with the problem of the double dielectric layer, numerical calculation was performed only when the thickness and relative permittivity of the dielectric layers had the same value. Overall, as the resistivity of the uniform resistivity increased, the current density induced in the resistive strip decreased, the reflected power decreased, and the transmitted power relatively increased. The numerical results of the structure proposed in this paper are shown in good agreement compared to the results of PMM, a numerical analysis method of the existing paper.

Solution of E-polarized Scattering by a Resistive Strip Grating Between a Double Dielectric Layer Using FGMM (FGMM을 이용한 2중 유전체층 사이의 저항띠 격자구조에 의한 TM 산란 해)

  • Uei-Joong Yoon
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.641-646
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    • 2023
  • In this paper, TM(transverse magnetic) scattering problems by a resistive strip grating between a double dielectric layer are analyzed by using the FGMM(fourier galerkin moment method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the resistive boundary condition is applied to analysis of the resistive strip. Overall, as the uniform resistivity of the resistive strip increased, the size of the current density induced in the resistance band decreased, the reflected power decreased, and the transmitted power increased. In addition, As the thickness of the dielectric layer increased, the reflected power increased and the transmitted power relatively decreased. The numerical results of the structure proposed in this paper are shown in good agreement compared to the results of PMM, a numerical analysis method of the existing paper.

Epitaxial growth of Pt Thin Film on Basal-Plane Sapphire Using RF Magnetron Sputtering

  • 이종철;김신철;송종환;이충만
    • Proceedings of the Korean Vacuum Society Conference
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    • 1998.02a
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    • pp.41-41
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    • 1998
  • Rare earth metal films have been used as a buffer layer for growing ferroelectric t thin film or a seed layer for magnetic multilayer. But when it was deposited on s semiconductor substrates for the application of magneto-optic (MO) storage media, it i is difficult to exactly measure magnetic cons떠nts due to shunting current, and so it n needs to grow metal films on insulator substrate to reduce such effect. Recently, it w was reported that ultra-thin Pt layer were epitaxially grown on A12O:J by ion beam s sputtering in 비떠 high vacuum and it can be used as a seed layer for the growth of C Co-contained magnetic multilayer. In this stu$\phi$, Pt thin film were epi떠xially grown on AI2D3 ($\alpha$)OJ) by RF magnetron s sputtering. The crystalline structure was analyzed by transmission electron microscope ( (TEM) and Rutherford Back Scattering (RBS)/Ion Channeling. In TEM study, Pt was b believed to be twinned on AI잉3($\alpha$)01) su$\pi$ace about Pt(ll1) plane.Moreover, RBS c channeling spectra showed that minimum scattering yield of Pt(111)/AI2O:J(1$\alpha$)OJ) was 4 4% and Pt(11J)/AI2D3($\alpha$)OJ) had 3-fold symmetry.

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Structure Analysis of TiO Film on the MgO(001) Surface by Time-Of-Flight Impact-Collision Ion Scattering Spectroscopy (비행시간형 직층돌 이온산란 분광법을 사용한 MgO(001) 면에 성장된 TiO막의 구조해석)

  • Hwang, Yeon;Lee, Tae-Kun;Park, Byung-Kyu
    • Korean Journal of Crystallography
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    • v.13 no.2
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    • pp.57-62
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    • 2002
  • Time-of-flight impact-collision ion scattering spectroscopy (TOF-ICISS) was applied to study the geometrical structure of epitaxially grown TiO layers on a MgO(001) surface. The hetero-epitaxial TiO layer was deposited by thermal evaporation of titanium onto the MgO(001) surface and subsequent exposure to oxygen at 400℃. The well-ordered TiO structure was confirmed with the 1×1 RHEED pattern. TOF-ICISS results revealed that the TiO layer was formed at the on-top sites of the MgO(001) substrate and that the lateral lattice constant of TiO layer was the same as that of the MgO substrate. The surface of the deposited epitaxial TiO layer was smooth without the three dimensional islands.

A MEIS Study on Ge Eppitaxial Growth on Si(001) with dynamically supplied Atomic Hydrogen

  • Ha, Yong-Ho;Kahng, Se-Jong;Kim, Se-Hun;Kuk, Young;Kim, Hyung-Kyung;Moon, Dae-Won
    • Proceedings of the Korean Vacuum Society Conference
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    • 1998.02a
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    • pp.156-157
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    • 1998
  • It is a diffcult and challenging pproblem to control the growth of eppitaxial films. Heteroeppitaxy is esppecially idfficult because of the lattice mismatch between sub-strate and depposited layers. This mismatch leads usually to a three dimensional(3D) island growth. But the use of surfactants such as As, Sb, and Bi can be beneficial in obtaining high quality heteroeppitaxial films. In this study medium energy ion scattering sppectroscoppy(MEIS) was used in order to reveal the growth mode of Ge on Si(001) and the strain of depposited film without and with dynamically supplied atomic hydrogen at the growth thempperature of 35$0^{\circ}C$. It was ppossible to control the growth mode from layer-by-layer followed by 3D island to layer-by-layer by controlling the hydrogen flux. In the absent of hydro-gen the film grows in the layer-by-layer mode within the critical thickness(about 3ML) and the 3D island formation is followed(Fig1). The 3D island formation is suppressed by introducing hydrogen resulting in layer-by-layer growth beyond the critical thickness(Fig2) We measured angular shift of blocking dipp in order to obtain the structural information on the thin films. In the ppressence of atomic hydrogen the blocking 야 is shifted toward higher scattering angle about 1。. That means the film is distorted tetragonally and strained therefore(Fig4) In other case the shift of blocking dipp at 3ML is almost same as pprevious case. But above the critical thickness the pposition of blocking dipp is similar to that of Si bulk(Fig3). It means the films is relaxed from the first layer. There is 4.2% lattice mismatch between Ge and Si. That mismatch results in about 2。 shift of blocking dipp. We measured about 1。 shift. This fact could be due to the intermixing of Ge and Si. This expperimental results are consistent with Vegard's law which says that the lattice constant of alloys is linear combination of the lattic constants of the ppure materials.

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